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Baumann D, Van Helden D, Evans LC, Vulchanova L, Dayton A, Osborn JW. IL-1R Mediated Activation of Renal Sensory Nerves in DOCA-Salt Hypertension. Hypertension 2024; 81:1811-1821. [PMID: 38841853 PMCID: PMC11254549 DOI: 10.1161/hypertensionaha.123.22620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/20/2024] [Indexed: 06/07/2024]
Abstract
BACKGROUND Clinical trials of renal denervation for the treatment of hypertension have shown a variety of off-target improvements in conditions associated with sympathetic overactivity. This may be due to the ablation of sympathoexcitatory afferent renal nerves, which are overactive under conditions of renal inflammation. Renal IL (interleukin)-1β is elevated in the deoxycorticosterone acetate-salt model of hypertension, and its activity may be responsible for the elevation in afferent renal nerve activity and arterial pressure. METHODS Continuous blood pressure recording of deoxycorticosterone acetate-salt mice with IL-1R (IL-1 receptor) knockout or antagonism was used individually and combined with afferent renal denervation (ARDN) to assess mechanistic overlap. Protein quantification and histological analysis of kidneys were performed to characterize renal inflammation. RESULTS ARDN attenuated deoxycorticosterone acetate-salt hypertension (-20±2-Δmm Hg mean arterial pressure [MAP] relative to control at study end) to a similar degree as total renal denervation (-21±2-Δmm Hg MAP), IL-1R knockout (-16±4-Δmm Hg MAP), or IL-1R antagonism (-20±3-Δmm Hg MAP). The combination of ARDN with knockout (-18±2-Δmm Hg MAP) or antagonism (-19±4-Δmm Hg MAP) did not attenuate hypertension any further than ARDN alone. IL-1R antagonism was found to have an acute depressor effect (-15±3-Δmm Hg MAP, day 10) in animals with intact renal nerves but not those with ARDN. CONCLUSIONS These findings suggest that IL-1R signaling is partially responsible for the elevated afferent renal nerve activity, which stimulates central sympathetic outflow to drive deoxycorticosterone acetate-salt hypertension.
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Affiliation(s)
- Daniel Baumann
- Graduate Program in Integrative Biology and Physiology (D.B.), University of Minnesota, Minneapolis
- Department of Surgery (D.B., D.V.H., L.C.E., J.W.O.), University of Minnesota, Minneapolis
| | - Dusty Van Helden
- Department of Surgery (D.B., D.V.H., L.C.E., J.W.O.), University of Minnesota, Minneapolis
| | - Louise C Evans
- Department of Surgery (D.B., D.V.H., L.C.E., J.W.O.), University of Minnesota, Minneapolis
| | - Lucy Vulchanova
- Department of Neuroscience (L.V.), University of Minnesota, Minneapolis
| | - Alex Dayton
- Division of Nephrology and Hypertension (A.D.), University of Minnesota, Minneapolis
| | - John W Osborn
- Department of Surgery (D.B., D.V.H., L.C.E., J.W.O.), University of Minnesota, Minneapolis
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2
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Faniyan TS, Zhang X, Morgan DA, Robles J, Bathina S, Brookes PS, Rahmouni K, Perry RJ, Chhabra KH. A kidney-hypothalamus axis promotes compensatory glucose production in response to glycosuria. eLife 2024; 12:RP91540. [PMID: 39082939 PMCID: PMC11290820 DOI: 10.7554/elife.91540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024] Open
Abstract
The kidneys facilitate energy conservation through reabsorption of nutrients including glucose. Almost all the filtered blood glucose is reabsorbed by the kidneys. Loss of glucose in urine (glycosuria) is offset by an increase in endogenous glucose production to maintain normal energy supply in the body. How the body senses this glucose loss and consequently enhances glucose production is unclear. Using renal Slc2a2 (also known as Glut2) knockout mice, we demonstrate that elevated glycosuria activates the hypothalamic-pituitary-adrenal axis, which in turn drives endogenous glucose production. This phenotype was attenuated by selective afferent renal denervation, indicating the involvement of the afferent nerves in promoting the compensatory increase in glucose production. In addition, through plasma proteomics analyses we observed that acute phase proteins - which are usually involved in the body's defense mechanisms against a threat - were the top candidates which were either upregulated or downregulated in renal Slc2a2 KO mice. Overall, afferent renal nerves contribute to promoting endogenous glucose production in response to elevated glycosuria and loss of glucose in urine is sensed as a biological threat in mice. These findings may be useful in improving the efficiency of drugs like SGLT2 inhibitors that are intended to treat hyperglycemia by enhancing glycosuria but are met with a compensatory increase in endogenous glucose production.
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Affiliation(s)
- Tumininu S Faniyan
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Xinyi Zhang
- Department of Cellular and Molecular Physiology, Yale UniversityNew HavenUnited States
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of MedicineIowa CityUnited States
| | - Jorge Robles
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Siresha Bathina
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Paul S Brookes
- Department of Anesthesiology, University of Rochester Medical CenterRochesterUnited States
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of MedicineIowa CityUnited States
| | - Rachel J Perry
- Department of Cellular and Molecular Physiology, Yale UniversityNew HavenUnited States
| | - Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
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3
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Evans LC, Dailey-Krempel B, Lauar MR, Dayton A, Vulchanova L, Osborn JW. Renal interoception in health and disease. Auton Neurosci 2024; 255:103208. [PMID: 39128142 DOI: 10.1016/j.autneu.2024.103208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/19/2024] [Accepted: 07/26/2024] [Indexed: 08/13/2024]
Abstract
Catheter based renal denervation has recently been FDA approved for the treatment of hypertension. Traditionally, the anti-hypertensive effects of renal denervation have been attributed to the ablation of the efferent sympathetic renal nerves. In recent years the role of the afferent sensory renal nerves in the regulation of blood pressure has received increased attention. In addition, afferent renal denervation is associated with reductions in sympathetic nervous system activity. This suggests that reductions in sympathetic drive to organs other than the kidney may contribute to the non-renal beneficial effects observed in clinical trials of catheter based renal denervation. In this review we will provide an overview of the role of the afferent renal nerves in the regulation of renal function and the development of pathophysiologies, both renal and non-renal. We will also describe the central projections of the afferent renal nerves, to give context to the responses seen following their ablation and activation. Finally, we will discuss the emerging role of the kidney as an interoceptive organ. We will describe the potential role of the kidney in the regulation of interoceptive sensitivity and in this context, speculate on the possible pathological consequences of altered renal function.
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Affiliation(s)
- Louise C Evans
- Department of Surgery, University of Minnesota Medical School, Minneapolis 55455, United States of America
| | - Brianna Dailey-Krempel
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, United States of America
| | - Mariana R Lauar
- Department of Surgery, University of Minnesota Medical School, Minneapolis 55455, United States of America
| | - Alex Dayton
- Division of Nephrology and Hypertension, University of Minnesota Medical School, Minneapolis 55455, United States of America
| | - Lucy Vulchanova
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, United States of America
| | - John W Osborn
- Department of Surgery, University of Minnesota Medical School, Minneapolis 55455, United States of America.
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4
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Frame AA, Nist KM, Kim K, Puleo F, Moreira JD, Swaldi H, McKenna J, Wainford RD. Integrated renal and sympathetic mechanisms underlying the development of sex- and age-dependent hypertension and the salt sensitivity of blood pressure. GeroScience 2024:10.1007/s11357-024-01266-1. [PMID: 38976131 DOI: 10.1007/s11357-024-01266-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 06/25/2024] [Indexed: 07/09/2024] Open
Abstract
Aging is a non-modifiable understudied risk factor for hypertension. We hypothesized that sympathetically mediated activation of renal sodium reabsorption drives age-dependent hypertension and the salt sensitivity of blood pressure (BP). Using 3-, 8-, and 16-month-old male and female Sprague-Dawley rats as a model of normal aging, we assessed BP, indices of sympathetic tone, and the physiological responses to acute and chronic sodium challenge including sodium chloride cotransporter (NCC) regulation. The effects of renal nerve ablation and NCC antagonism were assessed in hypertensive male rats. We observed sex-dependent impaired renal sodium handling (24 h sodium balance (meq), male 3-month 0.36 ± 0.1 vs. 16-month 0.84 ± 0.2; sodium load excreted during 5% bodyweight isotonic saline volume expansion (%) male 3-month 77 ± 5 vs. 16-month 22 ± 8), hypertension (MAP (mmHg) male 3-month 123 ± 4 vs. 16-month 148 ± 6), and the salt sensitivity of BP in aged male, but not female, rats. Attenuated sympathoinhibitory afferent renal nerve (ARN) responses contributed to increased sympathetic tone and hypertension in male rats. Increased sympathetic tone contributes to renal sodium retention, in part through increased NCC activity via a dysfunctional with-no-lysine kinase-(WNK) STE20/SPS1-related proline/alanine-rich kinase signaling pathway, to drive hypertension and the salt sensitivity of BP in aged male rats. NCC antagonism and renal nerve ablation, which reduced WNK dysfunction and decreased NCC activity, attenuated age-dependent hypertension in male Sprague-Dawley rats. The contribution of an impaired sympathoinhibitory ARN reflex to sex- and age-dependent hypertension in an NCC-dependent manner, via an impaired WNK1/WNK4 dynamic, suggests this pathway as a mechanism-based target for the treatment of age-dependent hypertension.
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Affiliation(s)
- Alissa A Frame
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Kayla M Nist
- Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Kiyoung Kim
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Franco Puleo
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Jesse D Moreira
- Department of Health Sciences, Sargent College, Boston University, Boston, MA, USA
| | - Hailey Swaldi
- Division of Cardiology, Emory University School of Medicine, 1750 Haygood Drive, Atlanta, GA, N22030322, USA
| | - James McKenna
- Division of Cardiology, Emory University School of Medicine, 1750 Haygood Drive, Atlanta, GA, N22030322, USA
| | - Richard D Wainford
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
- Division of Cardiology, Emory University School of Medicine, 1750 Haygood Drive, Atlanta, GA, N22030322, USA.
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5
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Shinohara K. Renal denervation: a key approach to hypertension and cardiovascular disease. Hypertens Res 2024:10.1038/s41440-024-01776-7. [PMID: 38961280 DOI: 10.1038/s41440-024-01776-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/13/2024] [Accepted: 06/06/2024] [Indexed: 07/05/2024]
Abstract
Sympathetic activation plays a critical role in the development of hypertension and cardiovascular disease, including heart failure and arrhythmias. Renal nerves contribute to the regulation of blood pressure and fluid volume through renal sympathetic efferent nerves, and to the modulation of sympathetic outflow through renal sensory afferent nerves. Previous studies including ours suggest that selective afferent renal denervation with preservation of efferent renal nerves can significantly decrease central sympathetic outflow in animal models of hypertension with renal damage. In Dahl salt-sensitive rats fed high salt diet from an early age, a model of hypertensive heart failure, this central sympathoinhibition by afferent renal denervation may attenuate the development of heart failure without significant blood pressure reduction. Accumulating clinical evidence supports the efficacy of renal denervation as an antihypertensive treatment. However, it remains important to clarify the appropriate indications and predictors of responders to renal denervation in the treatment of hypertension. Several clinical studies suggest beneficial effects of renal denervation in patients with heart disease, with or without hypertension, although most were not sham-controlled. In particular, some clinical studies have demonstrated that renal denervation reduces the incidence of atrial fibrillation or cardiovascular events even without a significant antihypertensive effect. It is essential to accumulate more insightful data in patients undergoing renal denervation, to establish the efficacy of renal denervation in patients with cardiovascular disease in the clinical setting, and to elucidate the therapeutic mechanisms of renal denervation and the renal nerves-linked pathophysiology of cardiovascular disease in basic research. This review outlines the effects of renal denervation on sympathetic activity and organ damage in animal models of hypertension and hypertensive heart failure, including our own data. Beyond the antihypertensive effects, the beneficial effects of renal denervation on cardiovascular disease are also discussed based on clinical studies. Several animal and clinical studies suggest the cardioprotective effects of renal denervation even in the absence of significant blood pressure reduction, probably due to its sympathoinhibitory effects.
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Affiliation(s)
- Keisuke Shinohara
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
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6
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Li KH, Lin JM, Luo SQ, Li MY, Yang YY, Li MM, Xia PY, Su JZ. Afferent Renal Denervation Attenuates Sympathetic Overactivation From the Paraventricular Nucleus in Spontaneously Hypertensive Rats. Am J Hypertens 2024; 37:477-484. [PMID: 38459938 DOI: 10.1093/ajh/hpae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/06/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024] Open
Abstract
BACKGROUND The effectiveness of renal denervation (RDN) in reducing blood pressure and systemic sympathetic activity in hypertensive patients has been established. However, the underlying central mechanism remains unknown. This study aimed to investigate the role of RDN in regulating cardiovascular function via the central renin-angiotensin system (RAS) pathway. METHODS Ten-week-old spontaneously hypertensive rats (SHR) were subjected to selective afferent renal denervation (ADN) using capsaicin solution. We hypothesized that ADN would effectively reduce blood pressure and rebalance the RAS component of the paraventricular nucleus (PVN) in SHR. RESULTS The experimental results show that the ADN group exhibited significantly lower blood pressure, reduced systemic sympathetic activity, decreased chronic neuronal activation marker C-FOS expression in the PVN, and improved arterial baroreflex function, compared with the Sham group. Furthermore, ACE and AT1 protein expression was reduced while ACE2 and MAS protein expression was increased in the PVN of SHR after ADN. CONCLUSIONS These findings suggest that RDN may exert these beneficial effects through modulating the central RAS pathway.
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Affiliation(s)
- Kun-Hui Li
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China
- Department of Rehabilitation Medicine, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China
| | - Jie-Min Lin
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China
- Department of Rehabilitation Medicine, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China
| | - Si-Qi Luo
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China
- Department of Rehabilitation Medicine, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China
| | - Min-Yan Li
- Department of Rehabilitation and Health, Fujian Vocational College of Bioengineering, Fuzhou, China
| | - Yi-Yong Yang
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China
- Department of Rehabilitation Medicine, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China
| | - Meng-Meng Li
- Department of Cardiology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Pan-Yan Xia
- Department of Rehabilitation Medicine, The School of Health, Fujian Medical University, Fuzhou, China
| | - Jin-Zi Su
- Department of Cardiology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
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7
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Abdulla MH, AlMarabeh S, Bolger T, Lucking EF, O'Halloran KD, Johns EJ. Effects of intrarenal pelvic infusion of tumour necrosis factor-α and interleukin 1-β on reno-renal reflexes in anaesthetised rats. J Hypertens 2024; 42:1027-1038. [PMID: 38690904 DOI: 10.1097/hjh.0000000000003689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
OBJECTIVE Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves. METHODS In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1β (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin. RESULTS The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1β infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1β, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1β, by almost 80% below vehicle, again without effect on either MAP or HR. CONCLUSION The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1β. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response.
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Affiliation(s)
- Mohammed H Abdulla
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Sara AlMarabeh
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Tom Bolger
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Eric F Lucking
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Edward J Johns
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
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8
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Faniyan TS, Zhang X, Morgan DA, Robles J, Bathina S, Brookes PS, Rahmouni K, Perry RJ, Chhabra KH. A kidney-hypothalamus axis promotes compensatory glucose production in response to glycosuria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.01.555894. [PMID: 37790458 PMCID: PMC10542134 DOI: 10.1101/2023.09.01.555894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The kidneys facilitate energy conservation through reabsorption of nutrients including glucose. Almost all the filtered blood glucose is reabsorbed by the kidneys. Loss of glucose in urine (glycosuria) is offset by an increase in endogenous glucose production to maintain normal energy supply in the body. How the body senses this glucose loss and consequently enhances glucose production is unclear. Using renal Glut2 knockout mice, we demonstrate that elevated glycosuria activates the hypothalamic-pituitary-adrenal axis, which in turn drives endogenous glucose production. This phenotype was attenuated by selective afferent renal denervation, indicating the involvement of the afferent nerves in promoting the compensatory increase in glucose production. In addition, through plasma proteomics analyses we observed that acute phase proteins - which are usually involved in body's defense mechanisms against a threat - were the top candidates which were either upregulated or downregulated in renal Glut2 KO mice. Overall, afferent renal nerves contribute to promoting endogenous glucose production in response to elevated glycosuria and loss of glucose in urine is sensed as a biological threat in mice. These findings may be useful in improving efficiency of drugs like SGLT2 inhibitors that are intended to treat hyperglycemia by enhancing glycosuria but are met with a compensatory increase in endogenous glucose production.
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9
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Lauar MR, Evans LC, Van Helden D, Fink GD, Banek CT, Menani JV, Osborn JW. Renal and hypothalamic inflammation in renovascular hypertension: role of afferent renal nerves. Am J Physiol Regul Integr Comp Physiol 2023; 325:R411-R422. [PMID: 37519252 PMCID: PMC10639016 DOI: 10.1152/ajpregu.00072.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/30/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023]
Abstract
Renal denervation (RDN) is a potential therapy for drug-resistant hypertension. However, whether its effects are mediated by ablation of efferent or afferent renal nerves is not clear. Previous studies have implicated that renal inflammation and the sympathetic nervous system are driven by the activation of afferent and efferent renal nerves. RDN attenuated the renal inflammation and sympathetic activity in some animal models of hypertension. In the 2 kidney,1 clip (2K1C) model of renovascular hypertension, RDN also decreased sympathetic activity; however, mechanisms underlying renal and central inflammation are still unclear. We tested the hypothesis that the mechanisms by which total RDN (TRDN; efferent + afferent) and afferent-specific RDN (ARDN) reduce arterial pressure in 2K1C rats are the same. Male Sprague-Dawley rats were instrumented with telemeters to measure mean arterial pressure (MAP), and after 7 days, a clip was placed on the left renal artery. Rats underwent TRDN, ARDN, or sham surgery of the clipped kidney and MAP was measured for 6 wk. Weekly measurements of water intake (WI), urine output (UO), and urinary copeptin were conducted, and urine was analyzed for cytokines/chemokines. Neurogenic pressor activity (NPA) was assessed at the end of the protocol calculated by the depressor response after intraperitoneal injection of hexamethonium. Rats were euthanized and the hypothalamus and kidneys removed for measurement of cytokine content. MAP, NPA, WI, and urinary copeptin were significantly increased in 2K1C-sham rats, and these responses were abolished by both TRDN and ARDN. 2K1C-sham rats presented with renal and hypothalamic inflammation and these responses were largely mitigated by TRDN and ARDN. We conclude that RDN attenuates 2K1C hypertension primarily by ablation of afferent renal nerves which disrupts bidirectional renal neural-immune pathways.NEW & NOTEWORTHY Hypertension resulting from reduced perfusion of the kidney is dependent on renal sensory nerves, which are linked to inflammation in the kidney and hypothalamus. Afferent renal nerves are required for chronic increases in both water intake and vasopressin release observed following renal artery stenosis. Findings from this study suggest an important role of renal sensory nerves that has previously been underestimated in the pathogenesis of 2K1C hypertension.
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Affiliation(s)
- Mariana R Lauar
- Department of Surgery, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Physiology and Pathology, Dentistry School, São Paulo State University-UNESP, Araraquara, São Paulo, Brazil
| | - Louise C Evans
- Department of Surgery, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Dusty Van Helden
- Department of Surgery, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, United States
| | - Christopher T Banek
- Department of Physiology, University of Arizona Health Sciences, Tucson, Arizona, United States
| | - José V Menani
- Department of Physiology and Pathology, Dentistry School, São Paulo State University-UNESP, Araraquara, São Paulo, Brazil
| | - John W Osborn
- Department of Surgery, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
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10
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Becker BK, Grady CM, Markl AE, Torres Rodriguez AA, Pollock DM. Elevated renal afferent nerve activity in a rat model of endothelin B receptor deficiency. Am J Physiol Renal Physiol 2023; 325:F235-F247. [PMID: 37348026 PMCID: PMC10396274 DOI: 10.1152/ajprenal.00064.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/13/2023] [Accepted: 06/21/2023] [Indexed: 06/24/2023] Open
Abstract
Renal nerves have been an attractive target for interventions aimed at lowering blood pressure; however, the specific roles of renal afferent (sensory) versus efferent sympathetic nerves in mediating hypertension are poorly characterized. A number of studies have suggested that a sympathoexcitatory signal conveyed by renal afferents elicits increases in blood pressure, whereas other studies identified sympathoinhibitory afferent pathways. These sympathoinhibitory pathways have been identified as protective against salt-sensitive increases in blood pressure through endothelin B (ETB) receptor activation. We hypothesized that ETB-deficient (ETB-def) rats, which are devoid of functional ETB receptors except in adrenergic tissues, lack appropriate sympathoinhibition and have lower renal afferent nerve activity following a high-salt diet compared with transgenic controls. We found that isolated renal pelvises from high salt-fed ETB-def animals lack a response to a physiological stimulus, prostaglandin E2, compared with transgenic controls but respond equally to a noxious stimulus, capsaicin. Surprisingly, we observed elevated renal afferent nerve activity in intact ETB-def rats compared with transgenic controls under both normal- and high-salt diets. ETB-def rats have been previously shown to have heightened global sympathetic tone, and we also observed higher total renal sympathetic nerve activity in ETB-def rats compared with transgenic controls under both normal- and high-salt diets. These data indicate that ETB receptors are integral mediators of the sympathoinhibitory renal afferent reflex (renorenal reflex), and, in a genetic rat model of ETB deficiency, the preponderance of sympathoexcitatory renal afferent nerve activity prevails and may contribute to hypertension.NEW & NOTEWORTHY Here, we found that endothelin B receptors are an important contributor to renal afferent nerve responsiveness to a high-salt diet. Rats lacking endothelin B receptors have increased afferent nerve activity that is not responsive to a high-salt diet.
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Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Caroline M Grady
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alexa E Markl
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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11
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Stocker SD, Sullivan JB. Deletion of the Transient Receptor Potential Vanilloid 1 Channel Attenuates Sympathoexcitation and Hypertension and Improves Glomerular Filtration Rate in 2-Kidney-1-Clip Rats. Hypertension 2023; 80:1671-1682. [PMID: 37334698 PMCID: PMC10527253 DOI: 10.1161/hypertensionaha.123.21153] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/06/2023] [Indexed: 06/20/2023]
Abstract
BACKGROUND Renal denervation lowers arterial blood pressure in both clinical populations and multiple experimental models of hypertension. This therapeutic effect is partly attributed to the removal of overactive renal sensory nerves. The TRPV1 (transient receptor potential vanilloid 1) channel is highly expressed in renal sensory nerves and detects changes in noxious and mechanosensitive stimuli, pH, and chemokines. However, the extent to which TRPV1 channels contribute to 2-kidney-1-clip (2K1C) renovascular hypertension has not been tested. METHODS We generated a novel Trpv1-/- (TRPV1 knockout) rat using CRISPR/Cas9 and 26-bp deletion in exon 3 and induced 2K1C hypertension. RESULTS The majority (85%) of rat renal sensory neurons retrogradely labeled from the kidney were TRPV1-positive. Trpv1-/- rats lacked TRPV1 immunofluorescence in the dorsal root ganglia, had a delayed tail-flick response to hot but not cold water, and lacked an afferent renal nerve activity response to intrarenal infusion of the TRPV1 agonist capsaicin. Interestingly, 2K1C hypertension was significantly attenuated in male Trpv1-/- versus wild-type rats. 2K1C hypertension significantly increased the depressor response to ganglionic blockade, total renal nerve activity (efferent and afferent), and afferent renal nerve activity in wild-type rats, but these responses were attenuated in male Trpv1-/- rats. 2K1C hypertension was attenuated in female rats with no differences between female strains. Finally, glomerular filtration rate was reduced by 2K1C in wild-type rats but improved in Trpv1-/- rats. CONCLUSIONS These findings suggest that renovascular hypertension requires activation of the TRPV1 channel to elevate renal afferent and sympathetic nerve activity, reduce glomerular filtration rate, and increase arterial blood pressure.
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Affiliation(s)
- Sean D Stocker
- Department of Neurobiology, University of Pittsburgh School of Medicine, PA
| | - Jacob B Sullivan
- Department of Neurobiology, University of Pittsburgh School of Medicine, PA
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12
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Parvin I, Gauthier MM, Dennis MR, Encinas NM, Nangia EL, Schwartz KL, Banek CT. Sequential afferent and sympathetic renal denervation impact on cardiovascular and renal homeostasis in the male Sprague-Dawley rat. Life Sci 2023; 325:121768. [PMID: 37169146 PMCID: PMC10225348 DOI: 10.1016/j.lfs.2023.121768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
Renal denervation (RDNx) is emerging as a promising treatment for cardiovascular disease, yet the underlying mechanisms and contributions of afferent (sensory) and efferent (sympathetic) renal nerves in healthy conditions remains limited. We hypothesize that sympathetic renal nerves contribute to long-term MAP and renal function, whereas afferent renal nerves do not contribute to the maintenance of cardiovascular and renal function. To test this hypothesis, we performed two experiments. In experiment one, we performed total renal denervation (T-RDNx), ablating afferent and sympathetic renal nerves, in normotensive adult SD rats to determine effects on MAP and renal function. Experiment 2 employed a sequential surgical ablation using: (1) afferent targeted renal denervation (A-RDNx), then (2) sympathetic (T-RDNx) denervation to determine the individual contributions to cardiovascular and renal homeostasis. In experiment 1, MAP decreased following T-RDNx and GFR increased. In experiment 2, A-RDNx led to an increase in MAP but did not change renal function. In contrast, T-RDNx decreased MAP and improved renal filtration. Together, these data partially support our hypothesis that renal sympathetic nerves contribute to the chronic regulation of arterial pressure and renal function. Contrary to the hypothesis, A-RDNx produced an increase in MAP without a detected change in renal function. We concluded that renal sympathetic nerves influence MAP and renal function regulation through a well-defined tonic contribution to renal vascular resistance and sodium reabsorption, whereas afferent renal nerves likely contribute to the maintenance of MAP through a tonic sympatho-inhibitory, negative feedback regulation in the normotensive, healthy rat.
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Affiliation(s)
- Irin Parvin
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Madeline M Gauthier
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Melissa R Dennis
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Noah M Encinas
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Ellen L Nangia
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Kyle L Schwartz
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Christopher T Banek
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ, USA.
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13
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Rodrigues AF, Todiras M, Qadri F, Alenina N, Bader M. Angiotensin deficient FVB/N mice are normotensive. Br J Pharmacol 2023; 180:1843-1861. [PMID: 36740662 DOI: 10.1111/bph.16051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/17/2023] [Accepted: 01/31/2023] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE All previous rodent models lacking the peptide hormone angiotensin II (Ang II) were hypotensive. A mixed background strain with global deletion of the angiotensinogen gene was backcrossed to the FVB/N background (Agt-KO), a strain preferred for transgenic generation. Surprisingly, the resulting line turned out to be normotensive. Therefore, this study aimed to understand the unique blood pressure regulation of FVB/N mice without angiotensin peptides. EXPERIMENTAL APPROACH Acute and chronic recordings of blood pressure (BP) in freely-moving adult mice were performed to establish baseline BP. The pressure responses to sympatholytic and sympathomimetic as well as a nitric oxide inhibitor and donor compounds were used to quantify the neurogenic tone and endothelial function. The role of the renal nerves on baseline BP maintenance was tested by renal denervation. Finally, further phenotyping was done by gene expression analysis, histology and measurement of metabolites in plasma, urine and tissues. KEY RESULTS Baseline BP in adult FVB/N Agt-KO was unexpectedly unaltered. As compensatory mechanisms Agt-KO presented an increased sympathetic nerve activity and reduced endothelial nitric oxide production. However, FVB/N Agt-KO exhibited the renal morphological and physiological alterations previously found in mice lacking the production of Ang II including polyuria and hydronephrosis. The hypotensive effect of bilateral renal denervation was blunted in Agt-KO compared to wildtype FVB/N mice. CONCLUSION AND IMPLICATIONS We describe a germline Agt-KO line that challenges all previous knowledge on BP regulation in mice with deletion of the classical RAS. This line may represent a model of drug-resistant hypertension because it lacks hypotension.
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Affiliation(s)
- André Felipe Rodrigues
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Department of Biology, Chemistry and Pharmacy, Free University of Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Mihail Todiras
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Nicolae Testemițanu State University of Medicine and Pharmacy, Chisinau, Moldova
| | - Fatimunnisa Qadri
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Natalia Alenina
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
- Charité Universitätsmedizin Berlin, Berlin, Germany
- Institute for Biology, University of Lübeck, Lübeck, Germany
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14
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Zhu Q, Xiao L, Cheng G, He J, Yin C, Wang L, Wang Q, Li L, Wei B, Weng Y, Geng F, Shen XZ, Shi P. Self-maintaining macrophages within the kidney contribute to salt and water balance by modulating kidney sympathetic nerve activity. Kidney Int 2023:S0085-2538(23)00343-5. [PMID: 37224917 DOI: 10.1016/j.kint.2023.04.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/26/2023]
Abstract
The kidney is critical in controlling salt and water balance, with the interstitium involved with a variety of components including immune cells in steady state. However, the roles of resident immune cells in kidney physiology are largely unknown. To help unravel some of these unknowns, we employed cell fate mapping, and identified a population of embryo-derived self-maintaining macrophages (SM-MØ) that were independent of the bone marrow in adult mouse kidneys. This kidney-specific SM-MØ population was distinctive from the kidney monocyte-derived macrophages in transcriptome and in their distribution. Specifically, the SM-MØ highly expressed nerve-associated genes; high-resolution confocal microscopy revealed that the SM-MØ in the cortex were in close association with sympathetic nerves and there was a dynamical interaction between macrophages and sympathetic nerves when live kidney sections were monitored. Kidney-specific depletion of the SM-MØ resulted in reduced sympathetic distribution and tone, leading to reduced renin secretion, increased glomerular filtration rate and solute diuresis, which caused salt decompensation and significant weight loss under a low-salt diet challenge. Supplementation of L-3,4-dihydroxyphenylserine which is converted to norepinephrine in vivo rescued the phenotype of SM-MØ-depleted mice. Thus, our findings provide insights in kidney macrophage heterogeneity and address a non-canonical role of macrophages in kidney physiology. In contrast to the well-appreciated way of central regulation, local regulation of sympathetic nerve distribution and activities in the kidney was uncovered.
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Affiliation(s)
- Qian Zhu
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Department of Cardiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liang Xiao
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Guo Cheng
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian He
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chunyou Yin
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liang Wang
- Department of Neurology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiang Wang
- Department of Laboratory Medicine, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Li Li
- Department of Pharmacy, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Bo Wei
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yuancheng Weng
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Fei Geng
- Department of Blood of Transfusion, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiao Z Shen
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;.
| | - Peng Shi
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China;.
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15
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Tyshynsky R, Sensarma S, Riedl M, Bukowy J, Schramm LP, Vulchanova L, Osborn JW. Periglomerular afferent innervation of the mouse renal cortex. Front Neurosci 2023; 17:974197. [PMID: 36777644 PMCID: PMC9909228 DOI: 10.3389/fnins.2023.974197] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Recent studies using a novel method for targeted ablation of afferent renal nerves have demonstrated their importance in the development and maintenance of some animal models of hypertension. However, relatively little is known about the anatomy of renal afferent nerves distal to the renal pelvis. Here, we investigated the anatomical relationship between renal glomeruli and afferent axons identified based on transient receptor potential vanilloid 1 channel (TRPV1) lineage or calcitonin gene related peptide (CGRP) immunolabeling. Analysis of over 6,000 (10,000 was accurate prior to the removal of the TH data during the review process) glomeruli from wildtype C57BL/6J mice and transgenic mice expressing tdTomato in TRPV1 lineage cells indicated that approximately half of all glomeruli sampled were closely apposed to tdTomato+ or CGRP+ afferent axons. Glomeruli were categorized as superficial, midcortical, or juxtamedullary based on their depth within the cortex. Juxtamedullary glomeruli were more likely to be closely apposed by afferent axon subtypes than more superficial glomeruli. High-resolution imaging of thick, cleared renal slices and subsequent distance transformations revealed that CGRP+ axons closely apposed to glomeruli were often found within 2 microns of nephrin+ labeling of glomerular podocytes. Furthermore, imaging of thick slices suggested that CGRP+ axon bundles can closely appose multiple glomeruli that share the same interlobular artery. Based on their expression of CGRP or tdTomato, prevalence near glomeruli, proximity to glomerular structures, and close apposition to multiple glomeruli within a module, we hypothesize that periglomerular afferent axons may function as mechanoreceptors monitoring glomerular pressure. These anatomical findings highlight the importance of further studies investigating the physiological role of periglomerular afferent axons in neural control of renal function in health and disease.
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Affiliation(s)
- Roman Tyshynsky
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Sulagna Sensarma
- Department of Surgery, University of Minnesota, Minneapolis, MN, United States
| | - Maureen Riedl
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - John Bukowy
- Department of Electrical Engineering and Computer Science, Milwaukee School of Engineering, Milwaukee, WI, United States
| | - Lawrence P. Schramm
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lucy Vulchanova
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States,Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - John W. Osborn
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States,Department of Surgery, University of Minnesota, Minneapolis, MN, United States,*Correspondence: John W. Osborn,
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16
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Contribution of afferent renal nerve signals to acute and chronic blood pressure regulation in stroke-prone spontaneously hypertensive rats. Hypertens Res 2023; 46:268-279. [PMID: 36369375 DOI: 10.1038/s41440-022-01091-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/13/2022]
Abstract
The activation of sympathetic nervous system plays a critical role in the development of hypertension. The input from afferent renal nerves may affect central sympathetic outflow; however, its contribution to the development of hypertension remains unclear. We investigated the role of afferent renal nerves in acute and chronic blood pressure regulation using normotensive Wistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Acute chemical stimulation of afferent renal nerves elicited larger increases in blood pressure and renal sympathetic nerve activity in young 9-week-old SHRSP compared to WKY. Selective afferent renal denervation (ARDN) and conventional total renal denervation (TRDN) ablating both afferent and efferent nerves in young SHRSP revealed that only TRDN, but not ARDN, chronically attenuated blood pressure elevation. ARDN did not affect plasma renin activity or plasma angiotensin II levels, whereas TRDN decreased both. Neither TRDN nor ARDN affected central sympathetic outflow and systemic sympathetic activity determined by neuronal activity in the parvocellular region of hypothalamic paraventricular nucleus and rostral ventrolateral medulla and by plasma and urinary norepinephrine levels, respectively. Renal injury was not apparent in young SHRSP compared with WKY, suggesting that renal afferent input might not be activated in young SHRSP. In conclusion, the chronic input from afferent renal nerves does not contribute to the development of hypertension in SHRSP despite the increased blood pressure response to the acute stimulation of afferent renal nerves. Efferent renal nerves may be involved in the development of hypertension via activation of the renin-angiotensin system in SHRSP.
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17
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Histological evidence supporting the durability of successful radiofrequency renal denervation in a normotensive porcine model. J Hypertens 2022; 40:2068-2075. [PMID: 35866489 PMCID: PMC9451943 DOI: 10.1097/hjh.0000000000003236] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Sustained blood pressure reductions after radiofrequency (RF) renal denervation (RDN) have been reported to 3 years in patients with uncontrolled hypertension. However, mechanistic data to support procedural durability are lacking. We aimed to quantify the long-term nerve anatomic and functional effects of RF RDN in a preclinical model. METHODS Bilateral RF RDN was performed in 20 normotensive swine. Renal tissue samples were obtained in the RDN-treated groups at 7 ( n = 6), 28 ( n = 6), and 180 days ( n = 8) postprocedure for quantification of cortical norepinephrine (NE) levels and renal cortical axon density. Tissue fibrosis, necrosis and downstream nerve fiber atrophy (axonal loss) were also scored for each sample. Three additional untreated groups ( n = 6, n = 6 and n = 8, respectively) served as control. RESULTS Pathologic nerve changes were characterized by necrosis in the ablated region at 7 days that partially resolved by 28 days and fully resolved at 180 days. Axonal loss was apparent within and downstream to the ablation regions and was evident at 7, 28 and 180 days in the main vessel and branch vessels. Consequently, renal cortical axon density and corresponding cortical NE levels were significantly reduced at 7 days in the RDN vs. control group and remained suppressed at 180 days. CONCLUSIONS Reductions in renal NE, cortical axon density and downstream axonal loss caused by axonal destruction persisted through 180 days post-RDN in a normotensive swine model. These results suggest functional nerve regrowth after RF RDN is unlikely and support published clinical evidence that the procedure results in durable blood pressure reduction.
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18
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DeLalio LJ, Stocker SD. Sympathoexcitatory responses to renal chemosensitive stimuli are exaggerated at nighttime in rats. Am J Physiol Heart Circ Physiol 2022; 323:H437-H448. [PMID: 35867707 PMCID: PMC9394783 DOI: 10.1152/ajpheart.00665.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/22/2022]
Abstract
The circadian cycle impacts sympathetic nerve activity (SNA), cardiovascular hemodynamics, and renal function. Activation of renal sensory nerves by chemosensory and mechanosensory stimuli reflexively changes efferent SNA and arterial blood pressure (ABP) to maintain homeostasis. However, it is unclear to what extent circadian cycle influences reflex SNA and ABP responses to renal sensory stimuli. Renal, splanchnic, and lumbar SNA and ABP responses to intrarenal arterial infusion of bradykinin or capsaicin and elevated renal pelvic pressure were measured in male and female Sprague-Dawley rats during nighttime (wakeful/active phase) and daytime (inactive phase). Intrarenal arterial bradykinin infusion significantly increased efferent renal SNA, splanchnic SNA, and ABP but not lumbar SNA. Responses were greater during nighttime versus daytime. Similarly, intrarenal arterial capsaicin infusion significantly increased renal SNA and splanchnic SNA, and responses were again greater during nighttime. Elevated renal pelvic pressure increased renal SNA and splanchnic SNA; however, responses did not differ between daytime and nighttime. Finally, afferent renal nerve activity responses to bradykinin were not different between daytime and nighttime. Thus, renal chemokines elicit greater sympathoexcitatory responses at nighttime that cannot be attributed to differences in afferent renal nerve activity. Collectively, these data suggest that the circadian cycle alters the excitability of central autonomic networks to alter baseline SNA and ABP as well as the magnitude of visceral reflexes.NEW & NOTEWORTHY The current study discovers that the circadian cycle influences sympathetic and hemodynamic responses to activation of renal chemosensitive sensory fibers. Sympathetic responses to intrarenal bradykinin or capsaicin infusion were exaggerated during nighttime (active period), but mechanosensitive responses to elevated renal pelvic pressure were not. Importantly, renal afferent nerve responses were not different between nighttime and daytime. These data suggest that the circadian cycle modulates sympathetic responses to visceral afferent activation.
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Affiliation(s)
- Leon J DeLalio
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sean D Stocker
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Mogi M, Maruhashi T, Higashi Y, Masuda T, Nagata D, Nagai M, Bokuda K, Ichihara A, Nozato Y, Toba A, Narita K, Hoshide S, Tanaka A, Node K, Yoshida Y, Shibata H, Katsurada K, Kuwabara M, Kodama T, Shinohara K, Kario K. Update on Hypertension Research in 2021. Hypertens Res 2022; 45:1276-1297. [PMID: 35790879 PMCID: PMC9255494 DOI: 10.1038/s41440-022-00967-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 12/16/2022]
Abstract
In 2021, 217 excellent manuscripts were published in Hypertension Research. Editorial teams greatly appreciate the authors' contribution to hypertension research progress. Here, our editorial members have summarized twelve topics from published work and discussed current topics in depth. We hope you enjoy our special feature, "Update on Hypertension Research in 2021".
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Affiliation(s)
- Masaki Mogi
- Department of Pharmacology, Ehime University Graduate School of Medicine, 454 Shitsukawa, Tohon, Ehime, 791-0295, Japan.
| | - Tatsuya Maruhashi
- Department of Regenerative Medicine, Division of Radiation Medical Science, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Yukihito Higashi
- Department of Regenerative Medicine, Division of Radiation Medical Science, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
- Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Takahiro Masuda
- Division of Nephrology, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Daisuke Nagata
- Division of Nephrology, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Michiaki Nagai
- Department of Cardiology, Hiroshima City Asa Hospital, 1-2-1 Kameyamaminami Asakita-ku, Hiroshima, 731-0293, Japan
| | - Kanako Bokuda
- Department of Endocrinology and Hypertension, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Atsuhiro Ichihara
- Department of Endocrinology and Hypertension, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Yoichi Nozato
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2, Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Ayumi Toba
- Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Keisuke Narita
- Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Satoshi Hoshide
- Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Atsushi Tanaka
- Department of Cardiovascular Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Koichi Node
- Department of Cardiovascular Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Yuichi Yoshida
- Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1, 1-1 Idaigaoka, Hasama-machi, Yufu city, Oita, 879-5593, Japan
| | - Hirotaka Shibata
- Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1, 1-1 Idaigaoka, Hasama-machi, Yufu city, Oita, 879-5593, Japan
| | - Kenichi Katsurada
- Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
- Division of Clinical Pharmacology, Department of Pharmacology, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Masanari Kuwabara
- Department of Cardiology, Toranomon Hospital, 2-2-2, Toranomon, Minato-ku, Tokyo, 105-8470, Japan
| | - Takahide Kodama
- Department of Cardiology, Toranomon Hospital, 2-2-2, Toranomon, Minato-ku, Tokyo, 105-8470, Japan
| | - Keisuke Shinohara
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kazuomi Kario
- Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
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Wu LL, Zhang Y, Li XZ, Du XL, Gao Y, Wang JX, Wang XL, Chen Q, Li YH, Zhu GQ, Tan X. Impact of Selective Renal Afferent Denervation on Oxidative Stress and Vascular Remodeling in Spontaneously Hypertensive Rats. Antioxidants (Basel) 2022; 11:1003. [PMID: 35624870 PMCID: PMC9137540 DOI: 10.3390/antiox11051003] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 02/01/2023] Open
Abstract
Oxidative stress and sustained sympathetic over-activity contribute to the pathogenesis of hypertension. Catheter-based renal denervation has been used as a strategy for treatment of resistant hypertension, which interrupts both afferent and efferent renal fibers. However, it is unknown whether selective renal afferent denervation (RAD) may play beneficial roles in attenuating oxidative stress and sympathetic activity in hypertension. This study investigated the impact of selective RAD on hypertension and vascular remodeling. Nine-week-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were subjected to selective renal afferent denervation (RAD) with 33 mM of capsaicin for 15 min. Treatment with the vehicle of capsaicin was used as a control. The selective denervation was confirmed by the reduced calcitonin gene-related peptide expression and the undamaged renal sympathetic nerve activity response to the stimulation of adipose white tissue. Selective RAD reduced plasma norepinephrine levels, improved heart rate variability (HRV) and attenuated hypertension in SHR.It reduced NADPH oxidase (NOX) expression and activity, and superoxide production in the hypothalamic paraventricular nucleus (PVN), aorta and mesenteric artery of SHR. Moreover, the selective RAD attenuated the vascular remodeling of the aorta and mesenteric artery of SHR. These results indicate that selective removal of renal afferents attenuates sympathetic activity, oxidative stress, vascular remodeling and hypertension in SHR. The attenuated superoxide signaling in the PVN is involved in the attenuation of sympathetic activity in SHR, and the reduced sympathetic activity at least partially contributes to the attenuation of vascular oxidative stress and remodeling in the arteries of hypertensive rats.
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Affiliation(s)
- Lu-Lu Wu
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing 211166, China; (L.-L.W.); (J.-X.W.); (X.-L.W.)
| | - Yue Zhang
- Emergency Department, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 211166, China; (Y.Z.); (X.-Z.L.); (X.-L.D.); (Y.G.)
| | - Xiu-Zhen Li
- Emergency Department, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 211166, China; (Y.Z.); (X.-Z.L.); (X.-L.D.); (Y.G.)
| | - Xin-Li Du
- Emergency Department, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 211166, China; (Y.Z.); (X.-Z.L.); (X.-L.D.); (Y.G.)
| | - Ying Gao
- Emergency Department, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 211166, China; (Y.Z.); (X.-Z.L.); (X.-L.D.); (Y.G.)
| | - Jing-Xiao Wang
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing 211166, China; (L.-L.W.); (J.-X.W.); (X.-L.W.)
| | - Xiao-Li Wang
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing 211166, China; (L.-L.W.); (J.-X.W.); (X.-L.W.)
| | - Qi Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing 211166, China; (Q.C.); (Y.-H.L.)
| | - Yue-Hua Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing 211166, China; (Q.C.); (Y.-H.L.)
| | - Guo-Qing Zhu
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing 211166, China; (L.-L.W.); (J.-X.W.); (X.-L.W.)
| | - Xiao Tan
- Emergency Department, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 211166, China; (Y.Z.); (X.-Z.L.); (X.-L.D.); (Y.G.)
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21
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Gauthier MM, Dennis MR, Morales MN, Brooks HL, Banek CT. Contribution of Afferent Renal Nerves to Cystogenesis and Arterial Pressure Regulation in a Preclinical Model of Autosomal Recessive Polycystic Kidney Disease. Am J Physiol Renal Physiol 2022; 322:F680-F691. [PMID: 35466689 PMCID: PMC9159540 DOI: 10.1152/ajprenal.00009.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Polycystic kidney disease (PKD) is the most common inheritable cause of kidney failure, and the underlying mechanisms remain incompletely uncovered. Renal nerves contribute to hypertension and chronic kidney disease - frequent complications of PKD. There is limited evidence that renal nerves may contribute to cardiorenal dysfunction in PKD, and no investigations of the role of sympathetic versus afferent nerves in PKD. Afferent renal nerve activity (ARNA) is elevated in models of renal disease and fibrosis. However, it remains unknown if this is true in PKD. We tested the hypothesis that ARNA is elevated in a preclinical model of autosomal recessive PKD (ARPKD), and that targeted renal nerve ablation would attenuate cystogenesis and cardiorenal dysfunction. We tested this by performing a total (T-RDNx) or afferent (A-RDNx) denervation in 4-week-old male and female PCK rats, then quantifying renal and cardiovascular responses 6 weeks following treatment. Cystogenesis was attenuated with A-RDNx and T-RDNx vs. sham controls, highlighting a crucial role for renal afferent nerves in cystogenesis. In contrast, blood pressure was improved with T-RDNx but not A-RDNx. Importantly, treatments produced similar results in both males and females. Direct renal afferent nerve recordings revealed that ARNA was 2-fold greater in PCK rats vs. non-cystic controls and was directly correlated to cystic severity. To our knowledge, we are the first to demonstrate that PCK rats have greater ARNA than non-cystic, age-matched controls. The findings of these studies support a novel and crucial role for renal afferent innervation in cystogenesis in the PCK rat.
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Affiliation(s)
- Madeline M Gauthier
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, United States
| | - Melissa R Dennis
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, United States
| | - Mark N Morales
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, United States
| | - Heddwen L Brooks
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, United States
| | - Christopher T Banek
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, United States.,Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
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22
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Renal denervation: basic and clinical evidence. Hypertens Res 2022; 45:198-209. [PMID: 34921299 DOI: 10.1038/s41440-021-00827-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 01/20/2023]
Abstract
Renal nerves have critical roles in regulating blood pressure and fluid volume, and their dysfunction is closely related with cardiovascular diseases. Renal nerves are composed of sympathetic efferent and sensory afferent nerves. Activation of the efferent renal sympathetic nerves induces renin secretion, sodium absorption, and increased renal vascular resistance, which lead to increased blood pressure and fluid retention. Afferent renal sensory nerves, which are densely innervated in the renal pelvic wall, project to the hypothalamic paraventricular nucleus in the brain to modulate sympathetic outflow to the periphery, including the heart, kidneys, and arterioles. The effects of renal denervation on the cardiovascular system are mediated by both efferent denervation and afferent denervation. The first half of this review focuses on basic research using animal models of hypertension and heart failure, and addresses the therapeutic effects of renal denervation for hypertension and heart failure, including underlying mechanisms. The second half of this review focuses on clinical research related to catheter-based renal denervation in patients with hypertension. Randomized sham-controlled trials using second-generation devices, endovascular radiofrequency-based devices and ultrasound-based devices are reviewed and their results are assessed. This review summarizes the basic and clinical evidence of renal denervation to date, and discusses future prospects and potential developments in renal denervation therapy for cardiovascular diseases.
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23
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AlMarabeh S, Lucking EF, O'Halloran KD, Abdulla MH. Intrarenal pelvic bradykinin-induced sympathoexcitatory reno-renal reflex is attenuated in rats exposed to chronic intermittent hypoxia. J Hypertens 2022; 40:46-64. [PMID: 34433765 DOI: 10.1097/hjh.0000000000002972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE In this study, we hypothesized that excitatory reno-renal reflex control of sympathetic outflow is enhanced in rats exposed to chronic intermittent hypoxia (CIH) with established hypertension. METHODS Under anaesthesia, renal sensory nerve endings in the renal pelvic wall were chemically activated using bradykinin (150, 400 and 700 μmol/l) and capsaicin (1.3 μmol/l), and cardiovascular parameters and renal sympathetic nerve activity (RSNA) were measured. RESULTS CIH-exposed rats were hypertensive with elevated basal heart rate and increased basal urine flow compared with sham. The intrarenal pelvic infusion of bradykinin was associated with contralateral increase in the RSNA and heart rate, without concomitant changes in blood pressure. This was associated with a drop in the glomerular filtration rate, which was significant during a 5 min period after termination of the infusion but without significant changes in urine flow and absolute sodium excretion. In response to intrarenal pelvic infusion of 700 μmol/l bradykinin, the increases in RSNA and heart rate were blunted in CIH-exposed rats compared with sham rats. Conversely, the intrarenal pelvic infusion of capsaicin evoked an equivalent sympathoexcitatory effect in CIH-exposed and sham rats. The blockade of bradykinin type 1 receptors (BK1R) suppressed the bradykinin-induced increase in RSNA by ∼33%, with a greater suppression obtained when bradykinin type 2 receptors (BK2R) and BK1R were contemporaneously blocked (∼66%). CONCLUSION Our findings reveal that the bradykinin-dependent excitatory reno-renal reflex does not contribute to CIH-induced sympathetic hyperactivity and hypertension. Rather, there is evidence that the excitatory reno-renal reflex is suppressed in CIH-exposed rats, which might relate to a downregulation of BK2R.
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Affiliation(s)
- Sara AlMarabeh
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
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24
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Mariano VS, Boer PA, Gontijo JAR. Fetal Undernutrition Programming, Sympathetic Nerve Activity, and Arterial Hypertension Development. Front Physiol 2021; 12:704819. [PMID: 34867434 PMCID: PMC8635863 DOI: 10.3389/fphys.2021.704819] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 10/14/2021] [Indexed: 12/11/2022] Open
Abstract
A wealth of evidence showed that low birth weight is associated with environmental disruption during gestation, triggering embryotic or fetal adaptations and increasing the susceptibility of progeny to non-communicable diseases, including metabolic and cardiovascular diseases, obesity, and arterial hypertension. In addition, dietary disturbance during pregnancy in animal models has highlighted mechanisms that involve the genesis of arterial hypertension, particularly severe maternal low-protein intake (LP). Functional studies demonstrated that maternal low-protein intake leads to the renal decrease of sodium excretion and the dysfunction of the renin-angiotensin-aldosterone system signaling of LP offspring. The antinatriuretic effect is accentuated by a reduced number of nephron units and glomerulosclerosis, which are critical in establishing arterial hypertension phenotype. Also, in this way, studies have shown that the overactivity of the central and peripheral sympathetic nervous system occurs due to reduced sensory (afferent) renal nerve activity. As a result of this reciprocal and abnormal renorenal reflex, there is an enhanced tubule sodium proximal sodium reabsorption, which, at least in part, contributes directly to arterial hypertension development in some of the programmed models. A recent study has observed that significant changes in adrenal medulla secretion could be involved in the pathophysiological process of increasing blood pressure. Thus, this review aims to compile studies that link the central and peripheral sympathetic system activity mechanisms on water and salt handle and blood pressure control in the maternal protein-restricted offspring. Besides, these pathophysiological mechanisms mainly may involve the modulation of neurokinins and catecholamines pathways.
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Affiliation(s)
- Vinícius Schiavinatto Mariano
- Fetal Programming and Hydroelectrolyte Metabolism Laboratory, Nucleus of Medicine and Experimental Surgery, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Patrícia Aline Boer
- Fetal Programming and Hydroelectrolyte Metabolism Laboratory, Nucleus of Medicine and Experimental Surgery, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - José Antônio Rocha Gontijo
- Fetal Programming and Hydroelectrolyte Metabolism Laboratory, Nucleus of Medicine and Experimental Surgery, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, São Paulo, Brazil
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25
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Moreira JD, Nist KM, Carmichael CY, Kuwabara JT, Wainford RD. Sensory Afferent Renal Nerve Activated Gαi 2 Subunit Proteins Mediate the Natriuretic, Sympathoinhibitory and Normotensive Responses to Peripheral Sodium Challenges. Front Physiol 2021; 12:771167. [PMID: 34916958 PMCID: PMC8669768 DOI: 10.3389/fphys.2021.771167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/09/2021] [Indexed: 11/15/2022] Open
Abstract
We have previously reported that brain Gαi2 subunit proteins are required to maintain sodium homeostasis and are endogenously upregulated in the hypothalamic paraventricular nucleus (PVN) in response to increased dietary salt intake to maintain a salt resistant phenotype in rats. However, the origin of the signal that drives the endogenous activation and up-regulation of PVN Gαi2 subunit protein signal transduction pathways is unknown. By central oligodeoxynucleotide (ODN) administration we show that the pressor responses to central acute administration and central infusion of sodium chloride occur independently of brain Gαi2 protein pathways. In response to an acute volume expansion, we demonstrate, via the use of selective afferent renal denervation (ADNX) and anteroventral third ventricle (AV3V) lesions, that the sensory afferent renal nerves, but not the sodium sensitive AV3V region, are mechanistically involved in Gαi2 protein mediated natriuresis to an acute volume expansion [peak natriuresis (μeq/min) sham AV3V: 43 ± 4 vs. AV3V 45 ± 4 vs. AV3V + Gαi2 ODN 25 ± 4, p < 0.05; sham ADNX: 43 ± 4 vs. ADNX 23 ± 6, AV3V + Gαi2 ODN 25 ± 3, p < 0.05]. Furthermore, in response to chronically elevated dietary sodium intake, endogenous up-regulation of PVN specific Gαi2 proteins does not involve the AV3V region and is mediated by the sensory afferent renal nerves to counter the development of the salt sensitivity of blood pressure (MAP [mmHg] 4% NaCl; Sham ADNX 124 ± 4 vs. ADNX 145 ± 4, p < 0.05; Sham AV3V 125 ± 4 vs. AV3V 121 ± 5). Additionally, the development of the salt sensitivity of blood pressure following central ODN-mediated Gαi2 protein down-regulation occurs independently of the actions of the brain angiotensin II type 1 receptor. Collectively, our data suggest that in response to alterations in whole body sodium the peripheral sensory afferent renal nerves, but not the central AV3V sodium sensitive region, evoke the up-regulation and activation of PVN Gαi2 protein gated pathways to maintain a salt resistant phenotype. As such, both the sensory afferent renal nerves and PVN Gαi2 protein gated pathways, represent potential targets for the treatment of the salt sensitivity of blood pressure.
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Affiliation(s)
- Jesse D. Moreira
- Whitaker Cardiovascular Institute, School of Medicine, Boston University, Boston, MA, United States
- Department of Medicine, School of Medicine, Boston University, Boston, MA, United States
| | - Kayla M. Nist
- Whitaker Cardiovascular Institute, School of Medicine, Boston University, Boston, MA, United States
- Department of Anatomy & Neurobiology, School of Medicine, Boston University, Boston, MA, United States
| | - Casey Y. Carmichael
- Whitaker Cardiovascular Institute, School of Medicine, Boston University, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Jill T. Kuwabara
- Whitaker Cardiovascular Institute, School of Medicine, Boston University, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Richard D. Wainford
- Whitaker Cardiovascular Institute, School of Medicine, Boston University, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
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26
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Effects of Renal Denervation on the Enhanced Renal Vascular Responsiveness to Angiotensin II in High-Output Heart Failure: Angiotensin II Receptor Binding Assessment and Functional Studies in Ren-2 Transgenic Hypertensive Rats. Biomedicines 2021; 9:biomedicines9121803. [PMID: 34944619 PMCID: PMC8698780 DOI: 10.3390/biomedicines9121803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/16/2021] [Accepted: 11/27/2021] [Indexed: 02/01/2023] Open
Abstract
Detailed mechanism(s) of the beneficial effects of renal denervation (RDN) on the course of heart failure (HF) remain unclear. The study aimed to evaluate renal vascular responsiveness to angiotensin II (ANG II) and to characterize ANG II type 1 (AT1) and type 2 (AT2) receptors in the kidney of Ren-2 transgenic rats (TGR), a model of ANG II-dependent hypertension. HF was induced by volume overload using aorto-caval fistula (ACF). The studies were performed two weeks after RDN (three weeks after the creation of ACF), i.e., when non-denervated ACF TGR enter the decompensation phase of HF whereas those after RDN are still in the compensation phase. We found that ACF TGR showed lower renal blood flow (RBF) and its exaggerated response to intrarenal ANG II (8 ng); RDN further augmented this responsiveness. We found that all ANG II receptors in the kidney cortex were of the AT1 subtype. ANG II receptor binding characteristics in the renal cortex did not significantly differ between experimental groups, hence AT1 alterations are not responsible for renal vascular hyperresponsiveness to ANG II in ACF TGR, denervated or not. In conclusion, maintained renal AT1 receptor binding combined with elevated ANG II levels and renal vascular hyperresponsiveness to ANG II in ACF TGR influence renal hemodynamics and tubular reabsorption and lead to renal dysfunction in the high-output HF model. Since RDN did not attenuate the RBF decrease and enhanced renal vascular responsiveness to ANG II, the beneficial actions of RDN on HF-related mortality are probably not dominantly mediated by renal mechanism(s).
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27
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Renal denervation based on experimental rationale. Hypertens Res 2021; 44:1385-1394. [PMID: 34518650 PMCID: PMC9577563 DOI: 10.1038/s41440-021-00746-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/03/2021] [Accepted: 08/16/2021] [Indexed: 02/07/2023]
Abstract
Excessive activation of the sympathetic nervous system is one of the pathophysiological hallmarks of hypertension and heart failure. Within the central nervous system, the paraventricular nucleus (PVN) of the hypothalamus and the rostral ventrolateral medulla in the brain stem play critical roles in the regulation of sympathetic outflow to peripheral organs. Information from the peripheral circulation, including serum concentrations of sodium and angiotensin II, is conveyed to the PVN via adjacent structures with a weak blood-brain barrier. In addition, signals from baroreceptors, chemoreceptors and cardiopulmonary receptors as well as afferent input via the renal nerves are all integrated at the level of the PVN. The brain renin-angiotensin system and the balance between nitric oxide and reactive oxygen species in these brain areas also determine the final sympathetic outflow. Additionally, brain inflammatory responses have been shown to modulate these processes. Renal denervation interrupts both the afferent inputs from the kidney to the PVN and the efferent outputs from the PVN to the kidney, resulting in the suppression of sympathetic outflow and eliciting beneficial effects on both hypertension and heart failure.
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28
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Dalmasso C, Leachman JR, Ghuneim S, Ahmed N, Schneider ER, Thibault O, Osborn JL, Loria AS. Epididymal Fat-Derived Sympathoexcitatory Signals Exacerbate Neurogenic Hypertension in Obese Male Mice Exposed to Early Life Stress. Hypertension 2021; 78:1434-1449. [PMID: 34601958 PMCID: PMC8516729 DOI: 10.1161/hypertensionaha.121.17298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/19/2021] [Indexed: 01/06/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Carolina Dalmasso
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
| | - Jacqueline R. Leachman
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
| | - Sundus Ghuneim
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
| | - Nermin Ahmed
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
| | - Eve R. Schneider
- Department of Biology, College of Arts and Sciences (E.R.S., J.L.O.), University of Kentucky, Lexington
| | - Olivier Thibault
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
| | - Jeffrey L. Osborn
- Department of Biology, College of Arts and Sciences (E.R.S., J.L.O.), University of Kentucky, Lexington
| | - Analia S. Loria
- Department of Pharmacology and Nutritional Sciences, College of Medicine (C.D., J.R.L., S.G., N.A., O.T., A.S.L.), University of Kentucky, Lexington
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29
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Sata Y, Burke SL, Eikelis N, Watson AMD, Gueguen C, Jackson KL, Lambert GW, Lim K, Denton KM, Schlaich MP, Head GA. Renal Deafferentation Prevents Progression of Hypertension and Changes to Sympathetic Reflexes in a Rabbit Model of Chronic Kidney Disease. Hypertension 2021; 78:1310-1321. [PMID: 34538104 DOI: 10.1161/hypertensionaha.121.17037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Yusuke Sata
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Faculty of Medicine, Nursing and Health Sciences, Central Clinical School (Y.S.), Monash University, Melbourne, VIC, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, VIC, Australia (Y.S.)
| | - Sandra L Burke
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Nina Eikelis
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Iverson Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC, Australia (N.E., G.W.L.)
| | - Anna M D Watson
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Diabetes, Central Clinical School (A.M.D.W.), Monash University, Melbourne, VIC, Australia
| | - Cindy Gueguen
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Kristy L Jackson
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences (K.L.J), Monash University, Melbourne, VIC, Australia
| | - Gavin W Lambert
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Iverson Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC, Australia (N.E., G.W.L.)
| | - Kyungjoon Lim
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia (K.L.)
| | - Kate M Denton
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC, Australia (K.M.D.)
| | - Markus P Schlaich
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Departments of Cardiology and Nephrology, Dobney Hypertension Centre, School of Medicine, Royal Perth Hospital Unit, University of Western Australia, Royal Perth Hospital (M.P.S.)
| | - Geoffrey A Head
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology (G.A.H.), Monash University, Melbourne, VIC, Australia
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30
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DeLalio LJ, Stocker SD. Impact of anesthesia and sex on sympathetic efferent and hemodynamic responses to renal chemo- and mechanosensitive stimuli. J Neurophysiol 2021; 126:668-679. [PMID: 34259043 DOI: 10.1152/jn.00277.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Activation of renal sensory nerves by chemo- and mechanosensitive stimuli produces changes in efferent sympathetic nerve activity (SNA) and arterial blood pressure (ABP). Anesthesia and sex influence autonomic function and cardiovascular hemodynamics, but it is unclear to what extent anesthesia and sex impact SNA and ABP responses to renal sensory stimuli. We measured renal, splanchnic, and lumbar SNA and ABP in male and female Sprague-Dawley rats during contralateral renal infusion of capsaicin and bradykinin or during elevation in renal pelvic pressure. Responses were evaluated with a decerebrate preparation or Inactin, urethane, or isoflurane anesthesia. Intrarenal arterial infusion of capsaicin (0.1-30.0 μM) increased renal SNA, splanchnic SNA, or ABP but decreased lumbar SNA in the Inactin group. Intrarenal arterial infusion of bradykinin (0.1-30.0 μM) increased renal SNA, splanchnic SNA, and ABP but decreased lumbar SNA in the Inactin group. Elevated renal pelvic pressure (0-20 mmHg, 30 s) significantly increased renal SNA and splanchnic SNA but not lumbar SNA in the Inactin group. In marked contrast, SNA and ABP responses to every renal stimulus were severely blunted in the urethane and decerebrate groups and absent in the isoflurane group. In the Inactin group, the magnitude of SNA responses to chemo- and mechanosensory stimuli were not different between male and female rats. Thus, chemo- and mechanosensitive stimuli produce differential changes in renal, splanchnic, and lumbar SNA. Experimentally, future investigations should consider Inactin anesthesia to examine sympathetic and hemodynamic responses to renal sensory stimuli.NEW & NOTEWORTHY The findings highlight the impact of anesthesia, and to a lesser extent sex, on sympathetic efferent and hemodynamic responses to chemosensory and mechanosensory renal stimuli. Sympathetic nerve activity (SNA) and arterial blood pressure (ABP) responses were present in Inactin-anesthetized rats but largely absent in decerebrate, isoflurane, or urethane preparations. Renal chemosensory stimuli differentially changed SNA: renal and splanchnic SNA increased, but lumbar SNA decreased. Future investigations should consider Inactin anesthesia to study SNA and hemodynamic responses to renal sensory nerve activation.
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Affiliation(s)
- Leon J DeLalio
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sean D Stocker
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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Li S, Hildreth CM, Rahman AA, Barton SA, Wyse BF, Lim CK, Pilowsky PM, Phillips JK. Renal denervation does not affect hypertension or the renin-angiotensin system in a rodent model of juvenile-onset polycystic kidney disease: clinical implications. Sci Rep 2021; 11:14286. [PMID: 34253766 PMCID: PMC8275789 DOI: 10.1038/s41598-021-93575-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/21/2021] [Indexed: 12/17/2022] Open
Abstract
We examined the effect of total and afferent renal denervation (RDN) on hypertension and the renin-angiotensin system (RAS) in a rodent model of juvenile-onset polycystic kidney disease (PKD). Lewis Polycystic Kidney (LPK) and control rats received total, afferent or sham RDN by periaxonal application of phenol, capsaicin or normal saline, respectively, and were monitored for 4-weeks. Afferent RDN did not affect systolic blood pressure (SBP) determined by radiotelemetry in either strain (n = 19) while total RDN significantly reduced SBP in Lewis rats 4-weeks post-denervation (total vs. sham, 122 ± 1 vs. 130 ± 2 mmHg, P = 0.002, n = 25). Plasma and kidney renin content determined by radioimmunoassay were significantly lower in LPK vs. Lewis (plasma: 278.2 ± 6.7 vs. 376.5 ± 11.9 ng Ang I/ml/h; kidney: 260.1 ± 6.3 vs. 753.2 ± 37.9 ng Ang I/mg/h, P < 0.001, n = 26). These parameters were not affected by RDN. Intrarenal mRNA expression levels of renin, angiotensinogen, angiotensin-converting enzyme (ACE)2, and angiotensin II receptor type 1a were significantly lower, whereas ACE1 expression was significantly higher in the LPK vs. Lewis (all P < 0.05, n = 26). This pattern of intrarenal RAS expression was not changed by RDN. In conclusion, RDN does not affect hypertension or the RAS in the LPK model and indicates RDN might not be a suitable antihypertensive strategy for individuals with juvenile-onset PKD.
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Affiliation(s)
- Sheran Li
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Cara M Hildreth
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Ahmed A Rahman
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Sean A Barton
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Benjamin F Wyse
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Chai K Lim
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Paul M Pilowsky
- Discipline of Physiology, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Jacqueline K Phillips
- Department of Biomedical Sciences, Faculty of Medicine, Human and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
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32
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Ye C, Zheng F, Wang JX, Wang XL, Chen Q, Li YH, Kang YM, Zhu GQ. Dysregulation of the Excitatory Renal Reflex in the Sympathetic Activation of Spontaneously Hypertensive Rat. Front Physiol 2021; 12:673950. [PMID: 34149454 PMCID: PMC8209386 DOI: 10.3389/fphys.2021.673950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/08/2021] [Indexed: 11/20/2022] Open
Abstract
Excessive sympathetic activation plays crucial roles in the pathogenesis of hypertension. Chemical stimulation of renal afferents increases the sympathetic activity and blood pressure in normal rats. This study investigated the excitatory renal reflex (ERR) in the development of hypertension in the spontaneously hypertensive rat (SHR). Experiments were performed in the Wistar-Kyoto rat (WKY) and SHR aged at 4, 12, and 24 weeks under anesthesia. Renal infusion of capsaicin was used to stimulate renal afferents, and thus, to induce ERR. The ERR was evaluated by the changes in the contralateral renal sympathetic nerve activity and mean arterial pressure. At the age of 4 weeks, the early stage with a slight or moderate hypertension, the ERR was more enhanced in SHR compared with WKY. The pressor response was greater than the sympathetic activation response in the SHR. At the age of 12 weeks, the development stage with severe hypertension, there was no significant difference in the ERR between the WKY and SHR. At the age of 24 weeks, the later stage of hypertension with long-term several hypertensions, the ERR was more attenuated in the SHR compared with the WKY. On the other hand, the pressor response to sympathetic activation due to the ERR was smaller at the age of 12 and 24 weeks than those at the age of 4 weeks. These results indicate that ERR is enhanced in the early stage of hypertension, and attenuated in the later stage of hypertension in the SHR. Abnormal ERR is involved in the sympathetic activation and the development of hypertension.
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Affiliation(s)
- Chao Ye
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Fen Zheng
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Jing-Xiao Wang
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Xiao-Li Wang
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Qi Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Yue-Hua Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Guo-Qing Zhu
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, Department of Physiology, Nanjing Medical University, Nanjing, China.,Department of Pathophysiology, Nanjing Medical University, Nanjing, China
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Selective afferent renal denervation mitigates renal and splanchnic sympathetic nerve overactivity and renal function in chronic kidney disease-induced hypertension. J Hypertens 2021; 38:765-773. [PMID: 31764582 DOI: 10.1097/hjh.0000000000002304] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Clinical and experimental evidence have shown that renal denervation, by removing both the sympathetic and afferent nerves, improves arterial hypertension and renal function in chronic kidney disease (CKD). Given the key role of renal sympathetic innervation in maintaining sodium and water homeostasis, studies have indicated that the total removal of renal nerves leads to impaired compensatory mechanisms during hemodynamic challenges. METHOD In the present study, we hypothesized that afferent (or sensory) fibers from the diseased kidney contribute to sympathetic overactivation to the kidney and other target organ, such as the splanchnic region, contributing to hypertension in CKD. We used a method to remove selectively the afferent renal fibers (periaxonal application of 33 mmol/l capsaicin) in a rat model of CKD, the 5/6 nephrectomy. RESULTS Three weeks after afferent renal denervation (ARD), we found a decrease in mean arterial pressure (∼15%) and normalization in renal and splanchnic sympathetic nerve hyperactivity in the CKD group. Interestingly, intrarenal renin--angiotensin system, as well as renal fibrosis and function and proteinuria were improved after ARD in CKD rats. CONCLUSION The findings demonstrate that afferent fibers contribute to the maintenance of arterial hypertension and reduced renal function that are likely to be mediated by increased sympathetic nerve activity to the renal territory as well as to other target organs in CKD.
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Osborn JW, Tyshynsky R, Vulchanova L. Function of Renal Nerves in Kidney Physiology and Pathophysiology. Annu Rev Physiol 2021; 83:429-450. [PMID: 33566672 DOI: 10.1146/annurev-physiol-031620-091656] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Renal sympathetic (efferent) nerves play an important role in the regulation of renal function, including glomerular filtration, sodium reabsorption, and renin release. The kidney is also innervated by sensory (afferent) nerves that relay information to the brain to modulate sympathetic outflow. Hypertension and other cardiometabolic diseases are linked to overactivity of renal sympathetic and sensory nerves, but our mechanistic understanding of these relationships is limited. Clinical trials of catheter-based renal nerve ablation to treat hypertension have yielded promising results. Therefore, a greater understanding of how renal nerves control the kidney under physiological and pathophysiological conditions is needed. In this review, we provide an overview of the current knowledge of the anatomy of efferent and afferent renal nerves and their functions in normal and pathophysiological conditions. We also suggest further avenues of research for development of novel therapies targeting the renal nerves.
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Affiliation(s)
- John W Osborn
- Department of Surgery, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA;
| | - Roman Tyshynsky
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Lucy Vulchanova
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Patel NJ, Heuser RR. Inside the kidney to treat hypertension: An alternative approach to renal denervation. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2021; 34:150-151. [PMID: 33593683 DOI: 10.1016/j.carrev.2021.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/05/2021] [Accepted: 02/05/2021] [Indexed: 11/03/2022]
Affiliation(s)
- Nachiket J Patel
- University of Arizona College of Medicine, Phoenix, AZ, United States of America; Southwest Cardiovascular Associates, Mesa, AZ, United States of America
| | - Richard R Heuser
- University of Arizona College of Medicine, Phoenix, AZ, United States of America; Vascular Heart and Lung Associates, Mesa, AZ, United States of America.
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DeLalio LJ, Stocker SD. Impact of anesthesia, sex, and circadian cycle on renal afferent nerve sensitivity. Am J Physiol Heart Circ Physiol 2021; 320:H117-H132. [PMID: 33216622 PMCID: PMC7847066 DOI: 10.1152/ajpheart.00675.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/17/2020] [Accepted: 11/17/2020] [Indexed: 01/09/2023]
Abstract
Elevated renal afferent nerve (ARNA) activity or dysfunctional reno-renal reflexes via altered ARNA sensitivity contribute to hypertension and chronic kidney disease. These nerves contain mechano- and chemosensitive fibers that respond to ischemia, changes in intrarenal pressures, and chemokines. Most studies have utilized various anesthetized preparations and exclusively male animals to characterize ARNA responses. Therefore, this study assessed the impact of anesthesia, sex, and circadian period on ARNA responses and sensitivity. Multifiber ARNA recordings were performed in male and female Sprague-Dawley rats (250-400 g) and compared across decerebrate versus Inactin, isoflurane, and urethane anesthesia groups. Intrarenal artery infusion of capsaicin (0.1-50.0 μM, 0.05 mL) produced concentration-dependent increases in ARNA; however, the ARNA sensitivity was significantly greater in decerebrate versus Inactin, isoflurane, and urethane groups. Increases in renal pelvic pressure (0-30 mmHg, 30 s) produced pressure-dependent increases in ARNA; however, ARNA sensitivity was again greater in decerebrate and Inactin groups versus isoflurane and urethane. Acute renal artery occlusion (30 s) increased ARNA, but responses did not differ across groups. Analysis of ARNA responses to increased pelvic pressure between male and female rats revealed significant sex differences only in isoflurane and urethane groups. ARNA responses to intrarenal capsaicin infusion were significantly blunted at nighttime versus daytime; however, ARNA responses to increased pelvic pressure or renal artery occlusion were not different between daytime and nighttime. These results demonstrate that ARNA sensitivity is greatest in decerebrate and Inactin-anesthetized groups but was not consistently influenced by sex.NEW & NOTEWORTHY We determined the impact of anesthesia, sex, and circadian cycle on renal afferent nerve (ARNA) sensitivity to chemical and mechanical stimuli. ARNA sensitivity to renal capsaicin infusion was greatest in decerebrate > Inactin > urethane or isoflurane groups. Elevated renal pelvic pressure significantly increased ARNA; decerebrate and Inactin groups exhibited the greatest ARNA sensitivity. Sex differences in renal afferent responses were not consistently observed. Circadian cycle altered chemosensory but not mechanosensory responses.
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Affiliation(s)
- Leon J DeLalio
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sean D Stocker
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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37
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AlMarabeh S, O'Neill J, Cavers J, Lucking EF, O'Halloran KD, Abdulla MH. Chronic intermittent hypoxia impairs diuretic and natriuretic responses to volume expansion in rats with preserved low-pressure baroreflex control of the kidney. Am J Physiol Renal Physiol 2021; 320:F1-F16. [PMID: 33166181 DOI: 10.1152/ajprenal.00377.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/26/2020] [Accepted: 11/03/2020] [Indexed: 12/17/2022] Open
Abstract
We examined the effects of exposure to chronic intermittent hypoxia (CIH) on baroreflex control of renal sympathetic nerve activity (RSNA) and renal excretory responses to volume expansion (VE) before and after intrarenal transient receptor potential vanilloid 1 (TRPV1) blockade by capsaizepine (CPZ). Male Wistar rats were exposed to 96 cycles of hypoxia per day for 14 days (CIH) or normoxia. Urine flow and absolute Na+ excretion during VE were less in CIH-exposed rats, but the progressive decrease in RSNA during VE was preserved. Assessment of the high-pressure baroreflex revealed an increase in the operating and response range of RSNA and decreased slope in CIH-exposed rats with substantial hypertension [+19 mmHg basal mean arterial pressure (MAP)] but not in a second cohort with modest hypertension (+12 mmHg). Intrarenal CPZ caused diuresis, natriuresis, and a reduction in MAP in sham-exposed (sham) and CIH-exposed rats. After intrarenal CPZ, diuretic and natriuretic responses to VE in CIH-exposed rats were equivalent to those of sham rats. TRPV1 expression in the renal pelvic wall was similar in both experimental groups. Exposure to CIH did not elicit glomerular hypertrophy, renal inflammation, or oxidative stress. We conclude that exposure to CIH 1) does not impair the low-pressure baroreflex control of RSNA; 2) has modest effects on the high-pressure baroreflex control of RSNA, most likely indirectly due to hypertension; 3) can elicit hypertension in the absence of kidney injury; and 4) impairs diuretic and natriuretic responses to fluid overload. Our results suggest that exposure to CIH causes renal dysfunction, which may be relevant to obstructive sleep apnea.
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Affiliation(s)
- Sara AlMarabeh
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Julie O'Neill
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Jeremy Cavers
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Eric F Lucking
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Mohammed H Abdulla
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
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Shenton FC, Campbell T, Jones JFX, Pyner S. Distribution and morphology of sensory and autonomic fibres in the subendocardial plexus of the rat heart. J Anat 2021; 238:36-52. [PMID: 32783212 PMCID: PMC7754995 DOI: 10.1111/joa.13284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/26/2020] [Accepted: 07/02/2020] [Indexed: 01/11/2023] Open
Abstract
Cardiac reflexes originating from sensory receptors in the heart ensure blood supply to vital tissues and organs in the face of constantly changing demands. Atrial volume receptors are mechanically sensitive vagal afferents which relay to the medulla and hypothalamus, affecting vasopressin release and renal sympathetic activity. To date, two anatomically distinct sensory endings have been identified which may subserve cardiac mechanosensation: end-nets and flower-spray endings. To map the distribution of atrial receptors in the subendocardial space, we have double-labelled rat right atrial whole mounts for neurofilament heavy chain (NFH) and synaptic vesicle protein 2 (SV2) and generated high-resolution maps of the rat subendocardial neural plexus at the cavo-atrial region. In order to elucidate the nature of these fibres, double labelling with synaptophysin (SYN) and either NFH, calcitonin gene-related peptide (CGRP), choline acetyltransferase (ChAT) or tyrosine hydroxylase (TH) was performed. The findings show that subendocardial nerve nets are denser at the superior cavo-atrial junction than the mid-atrial region. Adluminal plexuses had the finest diameters and stained positively for synaptic vesicles (SV2 and SYN), CGRP and TH. These plexuses may represent sympathetic post-ganglionic fibres and/or sensory afferents. The latter are candidate substrates for type B volume receptors which are excited by stretch during atrial filling. Deeper nerve fibres appeared coarser and may be cholinergic (positive staining for ChAT). Flower-spray endings were never observed using immunohistochemistry but were delineated clearly with the intravital stain methylene blue. We suggest that differing nerve fibre structures form the basis by which atrial deformation and hence atrial filling is reflected to the brain.
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Affiliation(s)
| | - Thomas Campbell
- Discipline of AnatomySchool of MedicineUniversity College DublinDublin 4Ireland
| | - James F. X. Jones
- Discipline of AnatomySchool of MedicineUniversity College DublinDublin 4Ireland
| | - Susan Pyner
- Department of BiosciencesDurham UniversityDurhamUK
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Veiga AC, Milanez MIO, Campos RR, Bergamaschi CT, Nishi EE. The involvement of renal afferents in the maintenance of cardiorenal diseases. Am J Physiol Regul Integr Comp Physiol 2021; 320:R88-R93. [PMID: 33146555 DOI: 10.1152/ajpregu.00225.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elevated sympathetic vasomotor activity is a common feature of cardiorenal diseases. Therefore, the sympathetic nervous system is an important therapeutic target, particularly the fibers innervating the kidneys. In fact, renal denervation has been applied clinically and shown promising results in patients with hypertension and chronic kidney disease. However, the underlying mechanisms involved in the cardiorenal protection induced by renal denervation have not yet been fully clarified. This mini-review highlights historical and recent aspects related to the role of renal sensory fibers in the control of cardiorenal function under normal conditions and in experimental models of cardiovascular disease. Results have demonstrated that alterations in renal sensory function participate in the maintenance of elevated sympathetic vasomotor activity and cardiorenal changes; as such, renal sensory fibers may be a potential therapeutic target for the treatment of cardiorenal diseases. Although it has not yet been applied in clinical practice, selective afferent renal denervation may be promising, since such an approach maintains efferent activity and can provide more refined control of renal function compared with total renal denervation. However, more studies are needed to understand the mechanisms by which renal afferents partially contribute to such changes, in addition to the need to evaluate the safety and advantages of the approach for application in the clinical practice.
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Affiliation(s)
- Amanda C Veiga
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Maycon I O Milanez
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Cassia T Bergamaschi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
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Milanez MIO, Veiga AC, Martins BS, Pontes RB, Bergamaschi CT, Campos RR, Nishi EE. Renal Sensory Activity Regulates the γ-Aminobutyric Acidergic Inputs to the Paraventricular Nucleus of the Hypothalamus in Goldblatt Hypertension. Front Physiol 2020; 11:601237. [PMID: 33384613 PMCID: PMC7769809 DOI: 10.3389/fphys.2020.601237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 12/27/2022] Open
Abstract
Renal sensory activity is centrally integrated within brain nuclei involved in the control of cardiovascular function, suggesting that renal afferents regulate basal and reflex sympathetic vasomotor activity. Evidence has shown that renal deafferentation (DAx) evokes a hypotensive and sympathoinhibitory effect in experimental models of cardiovascular diseases; however, the underlying mechanisms involved in this phenomenon need to be clarified, especially those related to central aspects. We aimed to investigate the role of renal afferents in the control of γ-aminobutyric acid (GABA)ergic inputs to the paraventricular nucleus (PVN) of the hypothalamus in renovascular hypertensive (2K1C) rats and their influence in the regulation of cardiovascular function. Hypertension was induced by clipping the left renal artery. After 4 weeks, renal DAx was performed by exposing the left renal nerve to a 33 mM capsaicin solution for 15 min. After 2 weeks of DAx, microinjection of muscimol into the PVN was performed in order to evaluate the influence of GABAergic activity in the PVN and its contribution to the control of renal sympathetic nerve activity (rSNA) and blood pressure (BP). Muscimol microinjected into the PVN triggered a higher drop in BP and rSNA in the 2K1C rats and renal DAx mitigated these responses. These results suggest that renal afferents are involved in the GABAergic changes found in the PVN of 2K1C rats. Although the functional significance of this phenomenon needs to be clarified, it is reasonable to speculate that GABAergic alterations occur to mitigate microglia activation-induced sympathoexcitation in the PVN of 2K1C rats.
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Affiliation(s)
- Maycon I O Milanez
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Amanda C Veiga
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Beatriz S Martins
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Roberto B Pontes
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cassia T Bergamaschi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Rodionova K, Veelken R, Hilgers KF, Paulus EM, Linz P, Fischer MJM, Schenker M, Reeh P, Tiegs G, Ott C, Schmieder R, Schiffer M, Amann K, Ditting T. Afferent renal innervation in anti-Thy1.1 nephritis in rats. Am J Physiol Renal Physiol 2020; 319:F822-F832. [PMID: 33017188 DOI: 10.1152/ajprenal.00063.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Afferent renal nerves exhibit a dual function controlling central sympathetic outflow via afferent electrical activity and influencing intrarenal immunological processes by releasing peptides such as calcitonin gene-related peptide (CGRP). We tested the hypothesis that increased afferent and efferent renal nerve activity occur with augmented release of CGRP in anti-Thy1.1 nephritis, in which enhanced CGRP release exacerbates inflammation. Nephritis was induced in Sprague-Dawley rats by intravenous injection of OX-7 antibody (1.75 mg/kg), and animals were investigated neurophysiologically, electrophysiologically, and pathomorphologically 6 days later. Nephritic rats exhibited proteinuria (169.3 ± 10.2 mg/24 h) with increased efferent renal nerve activity (14.7 ± 0.9 bursts/s vs. control 11.5 ± 0.9 bursts/s, n = 11, P < 0.05). However, afferent renal nerve activity (in spikes/s) decreased in nephritis (8.0 ± 1.8 Hz vs. control 27.4 ± 4.1 Hz, n = 11, P < 0.05). In patch-clamp recordings, neurons with renal afferents from nephritic rats showed a lower frequency of high activity following electrical stimulation (43.4% vs. 66.4% in controls, P < 0.05). In vitro assays showed that renal tissue from nephritic rats exhibited increased CGRP release via spontaneous (14 ± 3 pg/mL vs. 6.8 ± 2.8 pg/ml in controls, n = 7, P < 0.05) and stimulated mechanisms. In nephritic animals, marked infiltration of macrophages in the interstitium (26 ± 4 cells/mm2) and glomeruli (3.7 ± 0.6 cells/glomerular cross-section) occurred. Pretreatment with the CGRP receptor antagonist CGRP8-37 reduced proteinuria, infiltration, and proliferation. In nephritic rats, it can be speculated that afferent renal nerves lose their ability to properly control efferent sympathetic nerve activity while influencing renal inflammation through increased CGRP release.
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Affiliation(s)
- Kristina Rodionova
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Roland Veelken
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
| | - Karl F Hilgers
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Eva-Maria Paulus
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Peter Linz
- Department of Radiology, University of Erlangen, Erlangen, Germany
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martina Schenker
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Physiology and Pathophysiology, University Erlangen, Erlangen, Germany
| | - Peter Reeh
- Department of Physiology and Pathophysiology, University Erlangen, Erlangen, Germany
| | - Gisa Tiegs
- Center of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Ott
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
| | - Roland Schmieder
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Mario Schiffer
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Kerstin Amann
- Department of Nephropathology, University of Erlangen, Erlangen, Germany
| | - Tilmann Ditting
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
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42
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Zheng F, Ye C, Wan GW, Zhou B, Tong Y, Lei JZ, Chen Q, Li YH, Kang YM, Zhu GQ. Interleukin-1β in hypothalamic paraventricular nucleus mediates excitatory renal reflex. Pflugers Arch 2020; 472:1577-1586. [PMID: 32915316 DOI: 10.1007/s00424-020-02461-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/09/2020] [Accepted: 09/04/2020] [Indexed: 12/16/2022]
Abstract
Chemical stimulation of kidney causes sympathetic activation and pressor responses in rats. The excitatory renal reflex (ERR) is mediated by angiotensin type 1 receptor (AT1R) and superoxide anions in hypothalamic paraventricular nucleus (PVN). The aim of this study is to determine whether interleukin-1β (IL-1β) in the PVN mediates the ERR, and whether the IL-1β production in the PVN is dependent on the AT1R-superoxide anion signaling. Experiments were performed in adult rats under anesthesia. The ERR was induced by renal infusion of capsaicin, and evaluated by the responses of the contralateral renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP). Inhibition of IL-1β production with MCC950 in the PVN dose-dependently inhibited the capsaicin-induced ERR and sympathetic activation. The PVN microinjection of IL-1 receptor antagonist IL-1Ra or specific IL-1β antibody abolished the capsaicin-induced ERR, while IL-1β enhanced the ERR. Renal infusion of capsaicin promoted p65-NFκB phosphorylation and IL-1β production in the PVN, which were prevented by PVN microinjection of NADPH oxidase inhibitor apocynin or the superoxide anion scavenger tempol. The PVN microinjection of NFκB inhibitor BMS-345541 abolished the capsaicin induced-ERR and IL-1β production, but not the NADPH oxidase activation and superoxide anion production. Furthermore, capsaicin-induced p65-NFκB phosphorylation and IL-1β production in the PVN were prevented by AT1R antagonist losartan, or angiotensin converting enzyme inhibitor captopril. These results indicate that capsaicin-induced ERR and sympathetic activation are mediated by IL-1β in the PVN. The IL-1β production in the PVN is dependent on the AT1R-mediated superoxide anion generation and NFκB activation.
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Affiliation(s)
- Fen Zheng
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Chao Ye
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Guo-Wei Wan
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Bing Zhou
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Ying Tong
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Jian-Zhen Lei
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Qi Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Yue-Hua Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an, 710061, China
| | - Guo-Qing Zhu
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center of Translational Medicine for Cardiovascular Disease, and Department of Physiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China. .,Department of Pathophysiology, Nanjing Medical University, Nanjing, 211166, Jiangsu, China.
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43
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Katsurada K, Nandi SS, Zheng H, Liu X, Sharma NM, Patel KP. GLP-1 mediated diuresis and natriuresis are blunted in heart failure and restored by selective afferent renal denervation. Cardiovasc Diabetol 2020; 19:57. [PMID: 32384887 PMCID: PMC7206815 DOI: 10.1186/s12933-020-01029-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023] Open
Abstract
Background Glucagon-like peptide-1 (GLP-1) induces diuresis and natriuresis. Previously we have shown that GLP-1 activates afferent renal nerve to increase efferent renal sympathetic nerve activity that negates the diuresis and natriuresis as a negative feedback mechanism in normal rats. However, renal effects of GLP-1 in heart failure (HF) has not been elucidated. The present study was designed to assess GLP-1-induced diuresis and natriuresis in rats with HF and its interactions with renal nerve activity. Methods HF was induced in rats by coronary artery ligation. The direct recording of afferent renal nerve activity (ARNA) with intrapelvic injection of GLP-1 and total renal sympathetic nerve activity (RSNA) with intravenous infusion of GLP-1 were performed. GLP-1 receptor expression in renal pelvis, densely innervated by afferent renal nerve, was assessed by real-time PCR and western blot analysis. In separate group of rats after coronary artery ligation selective afferent renal denervation (A-RDN) was performed by periaxonal application of capsaicin, then intravenous infusion of GLP-1-induced diuresis and natriuresis were evaluated. Results In HF, compared to sham-operated control; (1) response of increase in ARNA to intrapelvic injection of GLP-1 was enhanced (3.7 ± 0.4 vs. 2.0 ± 0.4 µV s), (2) GLP-1 receptor expression was increased in renal pelvis, (3) response of increase in RSNA to intravenous infusion of GLP-1 was enhanced (132 ± 30% vs. 70 ± 16% of the baseline level), and (4) diuretic and natriuretic responses to intravenous infusion of GLP-1 were blunted (urine flow 53.4 ± 4.3 vs. 78.6 ± 4.4 µl/min/gkw, sodium excretion 7.4 ± 0.8 vs. 10.9 ± 1.0 µEq/min/gkw). A-RDN induced significant increases in diuretic and natriuretic responses to GLP-1 in HF (urine flow 96.0 ± 1.9 vs. 53.4 ± 4.3 µl/min/gkw, sodium excretion 13.6 ± 1.4 vs. 7.4 ± 0.8 µEq/min/gkw). Conclusions The excessive activation of neural circuitry involving afferent and efferent renal nerves suppresses diuretic and natriuretic responses to GLP-1 in HF. These pathophysiological responses to GLP-1 might be involved in the interaction between incretin-based medicines and established HF condition. RDN restores diuretic and natriuretic effects of GLP-1 and thus has potential beneficial therapeutic implication for diabetic HF patients.
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Affiliation(s)
- Kenichi Katsurada
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE, 68198-5850, USA
| | - Shyam S Nandi
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE, 68198-5850, USA
| | - Hong Zheng
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
| | - Xuefei Liu
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
| | - Neeru M Sharma
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE, 68198-5850, USA
| | - Kaushik P Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE, 68198-5850, USA.
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Weber MA, Kirtane AJ, Weir MR, Radhakrishnan J, Das T, Berk M, Mendelsohn F, Bouchard A, Larrain G, Haase M, Diaz-Cartelle J, Leon MB. The REDUCE HTN: REINFORCE. JACC Cardiovasc Interv 2020; 13:461-470. [DOI: 10.1016/j.jcin.2019.10.061] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/24/2019] [Accepted: 10/15/2019] [Indexed: 12/12/2022]
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45
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Fontes MAP, Marzano LAS, Silva CC, Silva ACSE. Renal sympathetic denervation for resistant hypertension: where do we stand after more than a decade. ACTA ACUST UNITED AC 2020; 42:67-76. [PMID: 31939995 PMCID: PMC7213935 DOI: 10.1590/2175-8239-jbn-2018-0213] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 08/18/2019] [Indexed: 01/11/2023]
Abstract
Despite the current availability of safe and efficient drugs for treating hypertension, a substantial number of patients are drug-resistant hypertensives. Aiming this condition, a relatively new approach named catheter-based renal denervation was developed. We have now a clinically relevant time window to review the efficacy of renal denervation for treating this form of hypertension. This short review addresses the physiological contribution of renal sympathetic nerves for blood pressure control and discusses the pros and cons of renal denervation procedure for the treatment of resistant hypertension.
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Affiliation(s)
| | | | - Carina Cunha Silva
- Departamento de Fisiologia e Biofísica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Ana Cristina Simões E Silva
- Departamento de Pediatria, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
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Morisawa N, Kitada K, Fujisawa Y, Nakano D, Yamazaki D, Kobuchi S, Li L, Zhang Y, Morikawa T, Konishi Y, Yokoo T, Luft FC, Titze J, Nishiyama A. Renal sympathetic nerve activity regulates cardiovascular energy expenditure in rats fed high salt. Hypertens Res 2020; 43:482-491. [PMID: 31932643 DOI: 10.1038/s41440-019-0389-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 01/20/2023]
Abstract
We recently reported that a 4% high-salt diet + saline for drinking (HS + saline) leads to a catabolic state, reduced heart rate, and suppression of cardiovascular energy expenditure in mice. We suggested that HS + saline reduces heart rate via the suppression of the sympathetic nervous system to compensate for the high salt intake-induced catabolic state. To test this hypothesis, we directly measured renal sympathetic nerve activity (RSNA) in conscious Sprague-Dawley (SD) rats using a radiotelemetry system. We confirmed that HS + saline induced a catabolic state. HS + saline decreased heart rate, while also reducing RSNA in SD rats. In contrast, Dahl salt-sensitive (DSS) rats exhibited no change in heart rate and increased RSNA during high salt intake. Renal denervation significantly decreased heart rate and attenuated the catabolic state independent of blood pressure in DSS rats fed HS + saline, suggesting that salt-sensitive animals were unable to decrease cardiovascular energy consumption due to abnormal renal sympathetic nerve activation during high salt intake. These findings support the hypothesis that RSNA mediates heart rate during high salt intake in SD rats. However, the insensitivity of heart rate and enhanced RSNA observed in DSS rats may be additional critical diagnostic factors for salt-sensitive hypertension. Renal denervation may benefit salt-sensitive hypertension by reducing its effects on catabolism and cardiovascular energy expenditure.
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Affiliation(s)
- Norihiko Morisawa
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan.,Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Kento Kitada
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan. .,Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore.
| | - Yoshihide Fujisawa
- Life Science Research Center, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Daisuke Nakano
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Daisuke Yamazaki
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan.,Division of Nephrology and Hypertension, Osaka City General Hospital, Osaka, Japan
| | - Shuhei Kobuchi
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo University of Health Sciences, Hyogo, Japan
| | - Lei Li
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yifan Zhang
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Morikawa
- Division of Nephrology and Hypertension, Osaka City General Hospital, Osaka, Japan
| | - Yoshio Konishi
- Division of Nephrology and Hypertension, Osaka City General Hospital, Osaka, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Friedrich C Luft
- Experimental & Clinical Research Center, a joint collaboration between Max-Delbrück Center for Molecular Medicine and Charité Universitätsmedizin, Berlin, Germany
| | - Jens Titze
- Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore.,Division of Nephrology, Duke University Medical Center, Durham, NC, USA.,Division of Nephrology and Hypertension, University Clinic Erlangen, Erlangen, Germany
| | - Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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47
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Lopes NR, Milanez MIO, Martins BS, Veiga AC, Ferreira GR, Gomes GN, Girardi AC, Carvalho PM, Nogueira FN, Campos RR, Bergamaschi CT, Nishi EE. Afferent innervation of the ischemic kidney contributes to renal dysfunction in renovascular hypertensive rats. Pflugers Arch 2020; 472:325-334. [PMID: 31925527 DOI: 10.1007/s00424-019-02346-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/27/2019] [Accepted: 12/30/2019] [Indexed: 12/21/2022]
Abstract
The ablation of renal nerves, by destroying both the sympathetic and afferent fibers, has been shown to be effective in lowering blood pressure in resistant hypertensive patients. However, experimental studies have reported that the removal of sympathetic fibers may lead to side effects, such as the impairment of compensatory cardiorenal responses during a hemodynamic challenge. In the present study, we evaluated the effects of the selective removal of renal afferent fibers on arterial hypertension, renal sympathetic nerve activity, and renal changes in a model of renovascular hypertension. After 4 weeks of clipping the left renal artery, afferent renal denervation (ARD) was performed by exposing the left renal nerve to a 33 mM capsaicin solution for 15 min. After 2 weeks of ARD, we found reduced MAP (~ 18%) and sympathoexcitation to both the ischemic and contralateral kidneys in the hypertensive group. Moreover, a reduction in reactive oxygen species was observed in the ischemic (76%) and contralateral (27%) kidneys in the 2K1C group. In addition, ARD normalized renal function markers and proteinuria and podocin in the contralateral kidney. Taken altogether, we show that the selective removal of afferent fibers is an effective method to reduce MAP and improve renal changes without compromising the function of renal sympathetic fibers in the 2K1C model. Renal afferent nerves may be a new target in neurogenic hypertension and renal dysfunction.
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Affiliation(s)
- Nathalia R Lopes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Maycon I O Milanez
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Beatriz S Martins
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Amanda C Veiga
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Giovanna R Ferreira
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Guiomar N Gomes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Adriana C Girardi
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Polliane M Carvalho
- Department of Biomaterials and Oral Biology, Dentistry Faculty, Universidade de São Paulo, São Paulo, Brazil
| | - Fernando N Nogueira
- Department of Biomaterials and Oral Biology, Dentistry Faculty, Universidade de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil.
- Cardiovascular and Respiratory Physiology Division, Department of Physiology, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu, 862, São Paulo, SP, 04023-060, Brazil.
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48
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Araujo M, Solis G, Welch WJ, Wilcox CS. Renal Nerve Deafferentation Attenuates the Fall in GFR during Intravenous Infusion of Furosemide in Anesthetized Rats. Kidney Blood Press Res 2020; 45:70-83. [PMID: 31896111 DOI: 10.1159/000504223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/17/2019] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Furosemide reduces the glomerular filtration rate (GFR) and increases the renal vascular resistance (RVR) despite inhibiting tubuloglomerular feedback but increases proximal tubule pressure, renin release, and renal nerve activity. OBJECTIVE This study tested the hypothesis that the fall in GFR with furosemide is due to volume depletion or activation of angiotensin type 1 (AT1) receptors or renal nerves. METHODS Furosemide was infused for 60 min at 1.0 mg·kg-1·h-1 in groups of 5-8 anesthetized rats. Additional groups received intravenous volume replacement to prevent fluid and Na+ losses or volume replacement plus losartan or plus sham denervation or plus renal denervation or renal nerve deafferentation. RESULTS At 60 min of infusion, furosemide alone reduced the GFR (-37 ± 4%; p < 0.01). This fall was not prevented by volume replacement or pretreatment with losartan, although losartan moderated the increase in RVR with furosemide (+44 ± 3 vs. +82 ± 7%; p < 0.01). Whereas the GFR fell after furosemide in rats after sham procedure (-31 ± 2%), it was not changed significantly after prior renal deafferentation. Proximal tubule pressure increased significantly but returned towards baseline over 60 min of furosemide, while urine output remained elevated, and GFR and renal blood flow depressed. CONCLUSIONS The fall in GFR over 60 min of furosemide infusion is independent of volume depletion or activation of AT1 receptors but is largely dependent on renal afferent nerves.
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Affiliation(s)
- Magali Araujo
- Hypertension Research Center andDivision of Nephrology and Hypertension, Georgetown University, Washington, District of Columbia, USA
| | - Glenn Solis
- Hypertension Research Center andDivision of Nephrology and Hypertension, Georgetown University, Washington, District of Columbia, USA
| | - William J Welch
- Hypertension Research Center andDivision of Nephrology and Hypertension, Georgetown University, Washington, District of Columbia, USA
| | - Christopher S Wilcox
- Hypertension Research Center andDivision of Nephrology and Hypertension, Georgetown University, Washington, District of Columbia, USA,
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49
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Banek CT, Gauthier MM, Van Helden DA, Fink GD, Osborn JW. Renal Inflammation in DOCA-Salt Hypertension. Hypertension 2019; 73:1079-1086. [PMID: 30879356 DOI: 10.1161/hypertensionaha.119.12762] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recent reports indicate that, in addition to treating hypertension, renal denervation (RDN) also mitigates renal inflammation. However, because RDN decreases renal perfusion pressure, it is unclear whether these effects are because of the direct effects of RDN on inflammatory signaling or secondary to decreased arterial pressure (AP). Therefore, this study was conducted to elucidate the contribution of renal nerves to renal inflammation in the deoxycorticosterone (DOCA)-salt rat, a model in which RDN decreases AP and abolishes renal inflammation. In Experiment 1, we assessed the temporal changes in renal inflammation by measuring renal cytokines and AP in DOCA-salt rats. Uninephrectomized (1K) adult male Sprague Dawley rats that received surgical RDN or sham (Sham) were administered DOCA (100 mg, SC) and 0.9% saline for 21 days. AP was measured by radiotelemetry, and urinary cytokine excretion was measured repeatedly. In Experiment 2, the contribution of renal nerves in renal inflammation was assessed in a 2-kidney DOCA-salt rat to control for renal perfusion pressure. DOCA-salt treatment was administered after unilateral (U-)RDN. In Experiment 1, DOCA-salt-induced increases in AP and renal inflammation (assessed by urinary cytokines) were attenuated by RDN versus Sham. In Experiment 2, GRO/KC (growth-related oncogene/keratinocyte chemoattractant), MCP (monocyte chemoattractant protein)-1, and macrophage infiltration were lower in the denervated kidney versus the contralateral Sham kidney. No differences in T-cell infiltration were observed. Together, these data support the hypothesis that renal nerves mediate, in part, the development of renal inflammation in the DOCA-salt rat independent of hypertension. The mechanisms and cell-specificity mediating these effects require further investigation.
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Affiliation(s)
- Christopher T Banek
- From the Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (C.T.B., M.M.G., D.A.V.H., J.W.O.)
| | - Madeline M Gauthier
- From the Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (C.T.B., M.M.G., D.A.V.H., J.W.O.)
| | - Dusty A Van Helden
- From the Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (C.T.B., M.M.G., D.A.V.H., J.W.O.)
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing (G.D.F.)
| | - John W Osborn
- From the Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (C.T.B., M.M.G., D.A.V.H., J.W.O.)
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50
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Abdulla MH, Brennan N, Ryan E, Sweeney L, Manning J, Johns EJ. Tacrolimus restores the high‐ and low‐pressure baroreflex control of renal sympathetic nerve activity in cisplatin‐induced renal injury rats. Exp Physiol 2019; 104:1726-1736. [DOI: 10.1113/ep087829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 08/22/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Mohammed H. Abdulla
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
| | - Nicola Brennan
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
| | - Eimear Ryan
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
| | - Linda Sweeney
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
| | - Jennifer Manning
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
| | - Edward J. Johns
- Department of Physiology, Western Gateway Building University College Cork College Road Cork Ireland
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