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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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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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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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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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Renal sympathetic activity: A key modulator of pressure natriuresis in hypertension. Biochem Pharmacol 2023; 208:115386. [PMID: 36535529 DOI: 10.1016/j.bcp.2022.115386] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Hypertension is a complex disorder ensuing necessarily from alterations in the pressure-natriuresis relationship, the main determinant of long-term control of blood pressure. This mechanism sets natriuresis to the level of blood pressure, so that increasing pressure translates into higher osmotically driven diuresis to reduce volemia and control blood pressure. External factors affecting the renal handling of sodium regulate the pressure-natriuresis relationship so that more or less natriuresis is attained for each level of blood pressure. Hypertension can thus only develop following primary alterations in the pressure to natriuresis balance, or by abnormal activity of the regulation network. On the other hand, increased sympathetic tone is a very frequent finding in most forms of hypertension, long regarded as a key element in the pathophysiological scenario. In this article, we critically analyze the interplay of the renal component of the sympathetic nervous system and the pressure-natriuresis mechanism in the development of hypertension. A special focus is placed on discussing recent findings supporting a role of baroreceptors as a component, along with the afference of reno-renal reflex, of the input to the nucleus tractus solitarius, the central structure governing the long-term regulation of renal sympathetic efferent tone.
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Pickny L, Hindermann M, Ditting T, Hilgers KF, Linz P, Ott C, Schmieder RE, Schiffer M, Amann K, Veelken R, Rodionova K. Myocardial infarction with a preserved ejection fraction-the impaired function of the cardio-renal baroreflex. Front Physiol 2023; 14:1144620. [PMID: 37082237 PMCID: PMC10110856 DOI: 10.3389/fphys.2023.1144620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/14/2023] [Indexed: 04/22/2023] Open
Abstract
Introduction: In experimental myocardial infarction with reduced ejection fraction causing overt congestive heart failure, the control of renal sympathetic nerve activity (RSNA) by the cardio-renal baroreflex was impaired. The afferent vagal nerve activity under these experimental conditions had a lower frequency at saturation than that in controls. Hence, by investigating respective first neurons in the nodose ganglion (NG), we wanted to test the hypothesis that after myocardial infarction with still-preserved ejection fraction, the cardiac afferent nerve pathway is also already impaired. Material and methods: A myocardial infarction was induced by coronary artery ligature. After 21 days, nodose ganglion neurons with cardiac afferents from rats with myocardial infarction were cultured. A current clamp was used to characterize neurons as "tonic," i.e., sustained action potential (AP) firing, or "phasic," i.e., <5 APs upon current injection. Cardiac ejection fraction was measured using echocardiography; RSNA was recorded to evaluate the sensitivity of the cardiopulmonary baroreflex. Renal and cardiac histology was studied for inflammation and fibrosis markers. Results: A total of 192 neurons were investigated. In rats, after myocardial infarction, the number of neurons with a tonic response pattern increased compared to that in the controls (infarction vs. control: 78.6% vs. 48.5%; z-test, *p < 0.05), with augmented production of APs (23.7 ± 2.86 vs. 15.5 ± 1.86 APs/600 ms; mean ± SEM, t-test, *p < 0.05). The baseline activity of RSNA was subtly increased, and its control by the cardiopulmonary baroreflex was impaired following myocardial infarction: the fibrosis marker collagen I augmented in the renal interstitium. Discussion: After myocardial infarction with still-preserved ejection fraction, a complex impairment of the afferent limb of the cardio-renal baroreflex caused dysregulation of renal sympathetic nerve activity with signs of renal fibrosis.
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Affiliation(s)
- Lisa Pickny
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Martin Hindermann
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Tilmann Ditting
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
- Department of Internal Medicine 4—Nephrology and Hypertension, Paracelsus Private Medical School Nuremberg, Nuremberg, Germany
| | - Karl F. Hilgers
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Peter Linz
- Department of Radiology, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Christian Ott
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
- Department of Internal Medicine 4—Nephrology and Hypertension, Paracelsus Private Medical School Nuremberg, Nuremberg, Germany
| | - Roland E. Schmieder
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Mario Schiffer
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Kerstin Amann
- Department of Nephropathology, Friedrich-Alexander University Erlangen, Erlangen, Germany
| | - Roland Veelken
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
- Department of Internal Medicine 4—Nephrology and Hypertension, Paracelsus Private Medical School Nuremberg, Nuremberg, Germany
- *Correspondence: Roland Veelken,
| | - Kristina Rodionova
- Department of Internal Medicine 4—Nephrology and Hypertension, Friedrich-Alexander University Erlangen, Erlangen, Germany
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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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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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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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10
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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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11
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Neurogenic substance P-influences on action potential production in afferent neurons of the kidney? Pflugers Arch 2021; 473:633-646. [PMID: 33786667 PMCID: PMC8049925 DOI: 10.1007/s00424-021-02552-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 12/23/2022]
Abstract
We recently showed that a substance P (SP)–dependent sympatho-inhibitory mechanism via afferent renal nerves is impaired in mesangioproliferative nephritis. Therefore, we tested the hypothesis that SP released from renal afferents inhibits the action potential (AP) production in their dorsal root ganglion (DRG) neurons. Cultured DRG neurons (Th11-L2) were investigated in current clamp mode to assess AP generation during both TRPV1 stimulation by protons (pH 6) and current injections with and without exposure to SP (0.5 µmol) or CGRP (0.5 µmol). Neurons were classified as tonic (sustained AP generation) or phasic (≤ 4 APs) upon current injection; voltage clamp experiments were performed for the investigation of TRPV1-mediated inward currents due to proton stimulation. Superfusion of renal neurons with protons and SP increased the number of action potentials in tonic neurons (9.6 ± 5 APs/10 s vs. 16.9 ± 6.1 APs/10 s, P < 0.05, mean ± SD, n = 7), while current injections with SP decreased it (15.2 ± 6 APs/600 ms vs. 10.2 ± 8 APs/600 ms, P < 0.05, mean ± SD, n = 29). Addition of SP significantly reduced acid-induced TRPV1-mediated currents in renal tonic neurons (− 518 ± 743 pA due to pH 6 superfusion vs. − 82 ± 50 pA due to pH 6 with SP superfusion). In conclusion, SP increased action potential production via a TRPV1-dependent mechanism in acid-sensitive renal neurons. On the other hand, current injection in the presence of SP led to decreased action potential production. Thus, the peptide SP modulates signaling pathways in renal neurons in an unexpected manner leading to both stimulation and inhibition of renal neuronal activity in different (e.g., acidic) environmental contexts.
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12
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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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13
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Frame AA, Carmichael CY, Kuwabara JT, Cunningham JT, Wainford RD. Role of the afferent renal nerves in sodium homeostasis and blood pressure regulation in rats. Exp Physiol 2019; 104:1306-1323. [PMID: 31074108 PMCID: PMC6675646 DOI: 10.1113/ep087700] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/09/2019] [Indexed: 12/11/2022]
Abstract
New Findings What is the central question of this study? What are the differential roles of the mechanosensitive and chemosensitive afferent renal nerves in the reno‐renal reflex that promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to sodium homeostasis? What is the main finding and its importance? The mechanosensitive afferent renal nerves contribute to an acute natriuretic sympathoinhibitory reno‐renal reflex that may be integrated within the paraventricular nucleus of the hypothalamus. Critically, the afferent renal nerves are required for the maintenance of salt resistance in Sprague–Dawley and Dahl salt‐resistant rats and attenuate the development of Dahl salt‐sensitive hypertension.
Abstract These studies tested the hypothesis that in normotensive salt‐resistant rat phenotypes the mechanosensitive afferent renal nerve (ARN) reno‐renal reflex promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to fluid and electrolyte homeostasis. Selective ARN ablation was conducted prior to (1) an acute isotonic volume expansion (VE) or 1 m NaCl infusion in Sprague–Dawley (SD) rats and (2) chronic high salt intake in SD, Dahl salt‐resistant (DSR), and Dahl salt‐sensitive (DSS) rats. ARN responsiveness following high salt intake was assessed ex vivo in response to noradrenaline and sodium concentration (SD, DSR and DSS) and via in vivo manipulation of renal pelvic pressure and sodium concentration (SD and DSS). ARN ablation attenuated the natriuretic and sympathoinhibitory responses to an acute VE [peak natriuresis (µeq min−1) sham 52 ± 5 vs. ARN ablation 28 ± 3, P < 0.05], but not a hypertonic saline infusion in SD rats. High salt (HS) intake enhanced ARN reno‐renal reflex‐mediated natriuresis in response to direct increases in renal pelvic pressure (mechanoreceptor stimulus) in vivo and ARN responsiveness to noradrenaline ex vivo in SD, but not DSS, rats. In vivo and ex vivo ARN responsiveness to increased renal pelvic sodium concentration (chemoreceptor stimulus) was unaltered during HS intake. ARN ablation evoked sympathetically mediated salt‐sensitive hypertension in SD rats [MAP (mmHg): sham normal salt 102 ± 2 vs. sham HS 104 ± 2 vs. ARN ablation normal salt 103 ± 2 vs. ARN ablation HS 121 ± 2, P < 0.05] and DSR rats and exacerbated DSS hypertension. The mechanosensitive ARNs mediate an acute sympathoinhibitory natriuretic reflex and counter the development of salt‐sensitive hypertension.
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Affiliation(s)
- Alissa A Frame
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Casey Y Carmichael
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Jill T Kuwabara
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - J Thomas Cunningham
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Richard D Wainford
- Department of Pharmacology & Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
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14
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Selective ablation of TRPV1 by intrathecal injection of resiniferatoxin in rats increases renal sympathoexcitatory responses and salt sensitivity. Hypertens Res 2018; 41:679-690. [PMID: 30006640 DOI: 10.1038/s41440-018-0073-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 01/03/2018] [Accepted: 01/09/2018] [Indexed: 01/28/2023]
Abstract
This study tested the hypothesis that selective ablation of transient receptor potential vanilloid type 1 (TRPV1)-positive nerve fibers by intrathecal injection of resiniferatoxin (RTX) enhances renal sympathoexcitatory responses and salt sensitivity. Intrathecal injection of RTX (1.8 μg/kg) to the levels of lower thoracic and upper lumbar spinal cord (T8-L3) increased mean arterial pressure (MAP) in rats fed a normal (NS, 1% NaCl) or high-sodium (HS, 8% NaCl) diet for 4 weeks compared to vehicle-treated rats (NS: 121 ± 2 vs. 111 ± 2; HS: 154 ± 2 vs. 134 ± 2 mm Hg, both P < 0.05), with a greater increase in HS compared to NS rats (9 ± 1% vs. 15 ± 1%, P < 0.05). TRPV1 contents were decreased in T8-L3 segments of spinal dorsal horn but not in corresponding dorsal root ganglia and the kidney following RTX treatment (P < 0.05). Selective activation of GABA-A receptors with intrathecal T8-L3 segment-injection of muscimol (3 nmol/kg) decreased renal sympathetic nerve activity and increased urinary excretion in both NS and HS rats, with a greater effect in RTX-treated compared to vehicle-treated rats (P < 0.05). Chronic activation of GABA-A receptors with muscimol (50 mg/kg/day × 2, p.o.) abolished RTX treatment-induced pressor effects in NS and HS rats. GAD65/67, a GABA synthetase, in the spinal cord was downregulated and tyrosine hydroxylase in the kidney upregulated in NS or HS rats treated with RTX (P < 0.05). Thus, selective ablation of TRPV1-positive central terminals of sensory neurons plays a prohypertensive role possibly via inhibition of spinal GABA system especially with HS intake, suggesting that activation of TRPV1 in central terminals of sensory neurons may convey an antihypertensive effect.
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15
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Okamura K, Satou S, Setojima K, Shono S, Miyajima S, Ishii T, Shirai K, Urata H. Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation. AMERICAN JOURNAL OF CASE REPORTS 2018; 19:567-572. [PMID: 29765015 PMCID: PMC5983072 DOI: 10.12659/ajcr.908891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Case series Patients: Male, 85 • Male, 89 Final Diagnosis: Essential hypertension Symptoms: High blood pressure Medication: Anti-hypertensive agents Clinical Procedure: Operation Specialty: Cardiology and Hypertension
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Affiliation(s)
- Keisuke Okamura
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Shunsuke Satou
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan.,Clinical Engineering Center, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Keita Setojima
- Clinical Engineering Center, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Shinjiro Shono
- Department of Anesthesiology, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Shigero Miyajima
- Department of Urology, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Tatsu Ishii
- Department of Urology, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Kazuyuki Shirai
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
| | - Hidenori Urata
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Chikushino, Fukuoka, Japan
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16
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Sata Y, Head GA, Denton K, May CN, Schlaich MP. Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension. Front Med (Lausanne) 2018; 5:82. [PMID: 29651418 PMCID: PMC5884873 DOI: 10.3389/fmed.2018.00082] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/15/2018] [Indexed: 12/18/2022] Open
Abstract
The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA) is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.
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Affiliation(s)
- Yusuke Sata
- Neurovascular Hypertension and Kidney Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Faculty of Medicine, Nursing and Health Sciences, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Geoffrey A Head
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Kate Denton
- Cardiovascular Program, Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Clive N May
- Preclinical Critical Care Unit, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Markus P Schlaich
- Neurovascular Hypertension and Kidney Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Faculty of Medicine, Nursing and Health Sciences, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit, University of Western Australia, Perth, WA, Australia
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17
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Banek CT, Gauthier MM, Baumann DC, Van Helden D, Asirvatham-Jeyaraj N, Panoskaltsis-Mortari A, Fink GD, Osborn JW. Targeted afferent renal denervation reduces arterial pressure but not renal inflammation in established DOCA-salt hypertension in the rat. Am J Physiol Regul Integr Comp Physiol 2018. [PMID: 29513561 DOI: 10.1152/ajpregu.00416.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent preclinical studies show renal denervation (RDNx) may be an effective treatment for hypertension; however, the mechanism remains unknown. We have recently reported total RDNx (TRDNx) and afferent-selective RDNx (ARDNx) similarly attenuated the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Whereas TRDNx abolished renal inflammation, ARDNx had a minimal effect despite an identical antihypertensive effect. Although this study established that ARDNx attenuates the development of DOCA-salt hypertension, it is unknown whether this mechanism remains operative once hypertension is established. The current study tested the hypothesis that TRDNx and ARDNx would similarly decrease mean arterial pressure (MAP) in the DOCA-salt hypertensive rat, and only TRDNx would mitigate renal inflammation. After 21 days of DOCA-salt treatment, male Sprague-Dawley rats underwent TRDNx ( n = 16), ARDNx ( n = 16), or Sham ( n = 14) treatment and were monitored for 14 days. Compared with baseline, TRDNx and ARDNx decreased MAP similarly (TRDNx -14 ± 4 and ARDNx -15 ± 6 mmHg). After analysis of diurnal rhythm, rhythm-adjusted mean and amplitude of night/day cycle were also reduced in TRDNx and ARDNx groups compared with Sham. Notably, no change in renal inflammation, injury, or function was detected with either treatment. We conclude from these findings that: 1) RDNx mitigates established DOCA-salt hypertension; 2) the MAP responses to RDNx are primarily mediated by ablation of afferent renal nerves; and 3) renal nerves do not contribute to the maintenance of renal inflammation in DOCA-salt hypertension.
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Affiliation(s)
- Christopher T Banek
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
| | - Madeline M Gauthier
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
| | - Daniel C Baumann
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
| | - Dusty Van Helden
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
| | | | | | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan
| | - John W Osborn
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
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18
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Abdulla MH, Johns EJ. The innervation of the kidney in renal injury and inflammation: a cause and consequence of deranged cardiovascular control. Acta Physiol (Oxf) 2017; 220:404-416. [PMID: 28181735 DOI: 10.1111/apha.12856] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/14/2016] [Accepted: 02/03/2017] [Indexed: 12/29/2022]
Abstract
Extensive investigations have revealed that renal sympathetic nerves regulate renin secretion, tubular fluid reabsorption and renal haemodynamics which can impact on cardiovascular homoeostasis normally and in pathophysiological states. The significance of the renal afferent innervation and its role in determining the autonomic control of the cardiovascular system is uncertain. The transduction pathways at the renal afferent nerves have been shown to require pro-inflammatory mediators and TRPV1 channels. Reno-renal reflexes have been described, both inhibitory and excitatory, demonstrating that a neural link exists between kidneys and may determine the distribution of excretory and haemodynamic function between the two kidneys. The impact of renal afferent nerve activity on basal and reflex regulation of global sympathetic drive remains opaque. There is clinical and experimental evidence that in states of chronic kidney disease and renal injury, there is infiltration of T-helper cells with a sympatho-excitation and blunting of the high- and low-pressure baroreceptor reflexes regulating renal sympathetic nerve activity. The baroreceptor deficits are renal nerve-dependent as the dysregulation can be relieved by renal denervation. There is also experimental evidence that in obese states, there is a sympatho-excitation and disrupted baroreflex regulation of renal sympathetic nerve activity which is mediated by the renal innervation. This body of information provides an important basis for directing greater attention to the role of renal injury/inflammation causing an inappropriate activation of the renal afferent nerves as an important initiator of aberrant autonomic cardiovascular control.
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Affiliation(s)
- M. H. Abdulla
- Department of Physiology; University College Cork; Cork Ireland
| | - E. J. Johns
- Department of Physiology; University College Cork; Cork Ireland
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19
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Abstract
The objective of this review is to provide an in-depth evaluation of how renal nerves regulate renal and cardiovascular function with a focus on long-term control of arterial pressure. We begin by reviewing the anatomy of renal nerves and then briefly discuss how the activity of renal nerves affects renal function. Current methods for measurement and quantification of efferent renal-nerve activity (ERNA) in animals and humans are discussed. Acute regulation of ERNA by classical neural reflexes as well and hormonal inputs to the brain is reviewed. The role of renal nerves in long-term control of arterial pressure in normotensive and hypertensive animals (and humans) is then reviewed with a focus on studies utilizing continuous long-term monitoring of arterial pressure. This includes a review of the effect of renal-nerve ablation on long-term control of arterial pressure in experimental animals as well as humans with drug-resistant hypertension. The extent to which changes in arterial pressure are due to ablation of renal afferent or efferent nerves are reviewed. We conclude by discussing the importance of renal nerves, relative to sympathetic activity to other vascular beds, in long-term control of arterial pressure and hypertension and propose directions for future research in this field. © 2017 American Physiological Society. Compr Physiol 7:263-320, 2017.
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Affiliation(s)
- John W Osborn
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jason D Foss
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
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20
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Banek CT, Knuepfer MM, Foss JD, Fiege JK, Asirvatham-Jeyaraj N, Van Helden D, Shimizu Y, Osborn JW. Resting Afferent Renal Nerve Discharge and Renal Inflammation: Elucidating the Role of Afferent and Efferent Renal Nerves in Deoxycorticosterone Acetate Salt Hypertension. Hypertension 2016; 68:1415-1423. [PMID: 27698066 DOI: 10.1161/hypertensionaha.116.07850] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 05/30/2016] [Accepted: 09/09/2016] [Indexed: 12/27/2022]
Abstract
Renal sympathetic denervation (RDNx) has emerged as a novel therapy for hypertension; however, the therapeutic mechanisms remain unclear. Efferent renal sympathetic nerve activity has recently been implicated in trafficking renal inflammatory immune cells and inflammatory chemokine and cytokine release. Several of these inflammatory mediators are known to activate or sensitize afferent nerves. This study aimed to elucidate the roles of efferent and afferent renal nerves in renal inflammation and hypertension in the deoxycorticosterone acetate (DOCA) salt rat model. Uninephrectomized male Sprague-Dawley rats (275-300 g) underwent afferent-selective RDNx (n=10), total RDNx (n=10), or Sham (n=10) and were instrumented for the measurement of mean arterial pressure and heart rate by radiotelemetry. Rats received 100-mg DOCA (SC) and 0.9% saline for 21 days. Resting afferent renal nerve activity in DOCA and vehicle animals was measured after the treatment protocol. Renal tissue inflammation was assessed by renal cytokine content and T-cell infiltration and activation. Resting afferent renal nerve activity, expressed as a percent of peak afferent nerve activity, was substantially increased in DOCA than in vehicle (35.8±4.4 versus 15.3±2.8 %Amax). The DOCA-Sham hypertension (132±12 mm Hg) was attenuated by ≈50% in both total RDNx (111±8 mm Hg) and afferent-selective RDNx (117±5 mm Hg) groups. Renal inflammation induced by DOCA salt was attenuated by total RDNx and unaffected by afferent-selective RDNx. These data suggest that afferent renal nerve activity may mediate the hypertensive response to DOCA salt, but inflammation may be mediated primarily by efferent renal sympathetic nerve activity. Also, resting afferent renal nerve activity is elevated in DOCA salt rats, which may highlight a crucial neural mechanism in the development and maintenance of hypertension.
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Affiliation(s)
- Christopher T Banek
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Mark M Knuepfer
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Jason D Foss
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Jessica K Fiege
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Ninitha Asirvatham-Jeyaraj
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Dusty Van Helden
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - Yoji Shimizu
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.)
| | - John W Osborn
- From the Department of Integrative Biology and Physiology (C.T.B., J.D.F., N.A.-J., D.V.H., J.W.O.) and Department of Laboratory Medicine and Pathology (J.K.F., Y.S), University of Minnesota Medical School, Minneapolis; and Department of Pharmacology and Physiology, Saint Louis University School of Medicine, MO (M.M.K.).
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21
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Koeners MP, Lewis KE, Ford AP, Paton JF. Hypertension: a problem of organ blood flow supply-demand mismatch. Future Cardiol 2016; 12:339-49. [PMID: 27091483 PMCID: PMC4926521 DOI: 10.2217/fca.16.5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
This review introduces a new hypothesis that sympathetically mediated hypertensive diseases are caused, in the most part, by the activation of visceral afferent systems that are connected to neural circuits generating sympathetic activity. We consider how organ hypoperfusion and blood flow supply–demand mismatch might lead to both sensory hyper-reflexia and aberrant afferent tonicity. We discuss how this may drive sympatho-excitatory-positive feedback and extend across multiple organs initiating, or at least amplifying, sympathetic hyperactivity. The latter, in turn, compounds the challenge to sufficient organ blood flow through heightened vasoconstriction that both maintains and exacerbates hypertension.
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Affiliation(s)
- Maarten P Koeners
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Kirsty E Lewis
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Anthony P Ford
- Afferent Pharmaceuticals, 2929 Campus Drive, San Mateo, CA, USA
| | - Julian Fr Paton
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
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22
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Ditting T, Freisinger W, Rodionova K, Schatz J, Lale N, Heinlein S, Linz P, Ott C, Schmieder RE, Scrogin KE, Veelken R. Impaired excitability of renal afferent innervation after exposure to the inflammatory chemokine CXCL1. Am J Physiol Renal Physiol 2015; 310:F364-71. [PMID: 26697980 DOI: 10.1152/ajprenal.00189.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 12/15/2015] [Indexed: 01/06/2023] Open
Abstract
Recently, we showed that renal afferent neurons exhibit a unique firing pattern, i.e., predominantly sustained firing, upon stimulation. Pathological conditions such as renal inflammation likely alter excitability of renal afferent neurons. Here, we tested whether the proinflammatory chemokine CXCL1 alters the firing pattern of renal afferent neurons. Rat dorsal root ganglion neurons (Th11-L2), retrogradely labeled with dicarbocyanine dye, were incubated with CXCL1 (20 h) or vehicle before patch-clamp recording. The firing pattern of neurons was characterized as tonic, i.e., sustained action potential (AP) firing, or phasic, i.e., <5 APs following current injection. Of the labeled renal afferents treated with vehicle, 58.9% exhibited a tonic firing pattern vs. 7.8%, in unlabeled, nonrenal neurons (P < 0.05). However, after exposure to CXCL1, significantly more phasic neurons were found among labeled renal neurons; hence the occurrence of tonic neurons with sustained firing upon electrical stimulation decreased (35.6 vs. 58.9%, P < 0.05). The firing frequency among tonic neurons was not statistically different between control and CXCL1-treated neurons. However, the lower firing frequency of phasic neurons was even further decreased with CXCL1 exposure [control: 1 AP/600 ms (1-2) vs. CXCL1: 1 AP/600 ms (1-1); P < 0.05; median (25th-75th percentile)]. Hence, CXCL1 shifted the firing pattern of renal afferents from a predominantly tonic to a more phasic firing pattern, suggesting that CXCL1 reduced the sensitivity of renal afferent units upon stimulation.
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Affiliation(s)
- Tilmann Ditting
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Wolfgang Freisinger
- Department of Internal Medicine 1, Nephrology Johannes-Guttenberg University, Mainz, Germany
| | - Kristina Rodionova
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Johannes Schatz
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Nena Lale
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Sonja Heinlein
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Peter Linz
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Christian Ott
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Roland E Schmieder
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany
| | - Karie E Scrogin
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago Stritch School of Medicine, Chicago, Illinois
| | - Roland Veelken
- Department of Internal Medicine 4, Nephrology and Hypertension, Friedrich-Alexander University, Erlangen, Germany;
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23
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Foss JD, Fink GD, Osborn JW. Differential role of afferent and efferent renal nerves in the maintenance of early- and late-phase Dahl S hypertension. Am J Physiol Regul Integr Comp Physiol 2015; 310:R262-7. [PMID: 26661098 DOI: 10.1152/ajpregu.00408.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/09/2015] [Indexed: 11/22/2022]
Abstract
Clinical data suggest that renal denervation (RDNX) may be an effective treatment for human hypertension; however, it is unclear whether this therapeutic effect is due to ablation of afferent or efferent renal nerves. We have previously shown that RDNX lowers arterial pressure in hypertensive Dahl salt-sensitive (S) rats to a similar degree observed in clinical trials. In addition, we have recently developed a method for selective ablation of afferent renal nerves (renal-CAP). In the present study, we tested the hypothesis that the antihypertensive effect of RDNX in the Dahl S rat is due to ablation of afferent renal nerves by comparing the effect of complete RDNX to renal-CAP during two phases of hypertension in the Dahl S rat. In the early phase, rats underwent treatment after 3 wk of high-NaCl feeding when mean arterial pressure (MAP) was ∼ 140 mmHg. In the late phase, rats underwent treatment after 9 wk of high NaCl feeding, when MAP was ∼ 170 mmHg. RDNX reduced MAP ∼ 10 mmHg compared with sham surgery in both the early and late phase, whereas renal-CAP had no antihypertensive effect. These results suggest that, in the Dahl S rat, the antihypertensive effect of RDNX is not dependent on pretreatment arterial pressure, nor is it due to ablation of afferent renal nerves.
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Affiliation(s)
- Jason D Foss
- University of Minnesota, Department of Integrative Biology and Physiology, Minneapolis, Minnesota; and
| | - Gregory D Fink
- Michigan State University, Department of Pharmacology and Toxicology, East Lansing, Michigan
| | - John W Osborn
- University of Minnesota, Department of Integrative Biology and Physiology, Minneapolis, Minnesota; and
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24
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Lin CS, Lee SH, Huang HS, Chen YS, Ma MC. H2O2 generated by NADPH oxidase 4 contributes to transient receptor potential vanilloid 1 channel-mediated mechanosensation in the rat kidney. Am J Physiol Renal Physiol 2015; 309:F369-76. [PMID: 26136558 DOI: 10.1152/ajprenal.00462.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 06/17/2015] [Indexed: 11/22/2022] Open
Abstract
The presence of NADPH oxidase (Nox) in the kidney, especially Nox4, results in H2O2 production, which regulates Na(+) excretion and urine formation. Redox-sensitive transient receptor potential vanilloid 1 channels (TRPV1s) are distributed in mechanosensory fibers of the renal pelvis and monitor changes in intrapelvic pressure (IPP) during urine formation. The present study tested whether H2O2 derived from Nox4 affects TRPV1 function in renal sensory responses. Perfusion of H2O2 into the renal pelvis dose dependently increased afferent renal nerve activity and substance P (SP) release. These responses were attenuated by cotreatment with catalase or TRPV1 blockers. In single unit recordings, H2O2 activated afferent renal nerve activity in response to rising IPP but not high salt. Western blots revealed that Nox2 (gp91(phox)) and Nox4 are both present in the rat kidney, but Nox4 is abundant in the renal pelvis and originates from dorsal root ganglia. This distribution was associated with expression of the Nox4 regulators p22(phox) and polymerase δ-interacting protein 2. Coimmunoprecipitation experiments showed that IPP increases polymerase δ-interacting protein 2 association with Nox4 or p22(phox) in the renal pelvis. Interestingly, immunofluorescence labeling demonstrated that Nox4 colocalizes with TRPV1 in sensory fibers of the renal pelvis, indicating that H2O2 generated from Nox4 may affect TRPV1 activity. Stepwise increases in IPP and saline loading resulted in H2O2 and SP release, sensory activation, diuresis, and natriuresis. These effects, however, were remarkably attenuated by Nox inhibition. Overall, these results suggest that Nox4-positive fibers liberate H2O2 after mechanostimulation, thereby contributing to a renal sensory nerve-mediated diuretic/natriuretic response.
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Affiliation(s)
- Chian-Shiung Lin
- Department of Surgery, Liou-Ying Hospital, Chi-Mei Medical Center, Tainan Hsien, Taiwan
| | - Shang-Hsing Lee
- Department of Urology, Cardinal Tien Hospital, New Taipei, Taiwan
| | - Ho-Shiang Huang
- Department of Urology, National Cheng Kung University, Tainan, Taiwan
| | - Yih-Sharng Chen
- Department of Cardiovascular Surgery, National Taiwan University Hospital, Taipei, Taiwan; and
| | - Ming-Chieh Ma
- School of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan
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25
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Kopp UC. Role of renal sensory nerves in physiological and pathophysiological conditions. Am J Physiol Regul Integr Comp Physiol 2015; 308:R79-95. [PMID: 25411364 PMCID: PMC4297860 DOI: 10.1152/ajpregu.00351.2014] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 11/02/2014] [Indexed: 12/26/2022]
Abstract
Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation.
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Affiliation(s)
- Ulla C Kopp
- Departments of Internal Medicine and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa
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26
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Foss JD, Wainford RD, Engeland WC, Fink GD, Osborn JW. A novel method of selective ablation of afferent renal nerves by periaxonal application of capsaicin. Am J Physiol Regul Integr Comp Physiol 2014; 308:R112-22. [PMID: 25411365 DOI: 10.1152/ajpregu.00427.2014] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Renal denervation has been shown to lower arterial pressure in some hypertensive patients, yet it remains unclear whether this is due to ablation of afferent or efferent renal nerves. To investigate the role of afferent renal nerves in arterial pressure regulation, previous studies have used methods that disrupt both renal and nonrenal afferent signaling. The present study was conducted to develop and validate a technique for selective ablation of afferent renal nerves that does not disrupt other afferent pathways. To do this, we adapted a technique for sensory denervation of the adrenal gland by topical application of capsaicin and tested the hypothesis that exposure of the renal nerves to capsaicin (renal-CAP) causes ablation of afferent but not efferent renal nerves. Renal-CAP had no effect on renal content of the efferent nerve markers tyrosine hydroxylase and norepinephrine; however, the afferent nerve marker, calcitonin gene-related peptide was largely depleted from the kidney 10 days after intervention, but returned to roughly half of control levels by 7 wk postintervention. Moreover, renal-CAP abolished the cardiovascular responses to acute pharmacological stimulation of afferent renal nerves. Renal-CAP rats showed normal weight gain, as well as cardiovascular and fluid balance regulation during dietary sodium loading. To some extent, renal-CAP did blunt the bradycardic response and increase the dipsogenic response to increased salt intake. Lastly, renal-CAP significantly attenuated the development of deoxycorticosterone acetate-salt hypertension. These results demonstrate that renal-CAP effectively causes selective ablation of afferent renal nerves in rats.
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Affiliation(s)
- Jason D Foss
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota
| | - Richard D Wainford
- Boston University School of Medicine, Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston, Massachusetts
| | | | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - John W Osborn
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota;
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27
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Wainford RD, Carmichael CY, Pascale CL, Kuwabara JT. Gαi2-protein-mediated signal transduction: central nervous system molecular mechanism countering the development of sodium-dependent hypertension. Hypertension 2014; 65:178-86. [PMID: 25312437 DOI: 10.1161/hypertensionaha.114.04463] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Excess dietary salt intake is an established cause of hypertension. At present, our understanding of the neuropathophysiology of salt-sensitive hypertension is limited by a lack of identification of the central nervous system mechanisms that modulate sympathetic outflow and blood pressure in response to dietary salt intake. We hypothesized that impairment of brain Gαi2-protein-gated signal transduction pathways would result in increased sympathetically mediated renal sodium retention, thus promoting the development of salt-sensitive hypertension. To test this hypothesis, naive or renal denervated Dahl salt-resistant and Dahl salt-sensitive (DSS) rats were assigned to receive a continuous intracerebroventricular control scrambled or a targeted Gαi2-oligodeoxynucleotide infusion, and naive Brown Norway and 8-congenic DSS rats were fed a 21-day normal or high-salt diet. High salt intake did not alter blood pressure, suppressed plasma norepinephrine, and evoked a site-specific increase in hypothalamic paraventricular nucleus Gαi2-protein levels in naive Brown Norway, Dahl salt-resistant, and scrambled oligodeoxynucleotide-infused Dahl salt-resistant but not DSS rats. In Dahl salt-resistant rats, Gαi2 downregulation evoked rapid renal nerve-dependent hypertension, sodium retention, and sympathoexcitation. In DSS rats, Gαi2 downregulation exacerbated salt-sensitive hypertension via a renal nerve-dependent mechanism. Congenic-8 DSS rats exhibited sodium-evoked paraventricular nucleus-specific Gαi2-protein upregulation and attenuated hypertension, sodium retention, and global sympathoexcitation compared with DSS rats. These data demonstrate that paraventricular nucleus Gαi2-protein-gated pathways represent a conserved central molecular pathway mediating sympathoinhibitory renal nerve-dependent responses evoked to maintain sodium homeostasis and a salt-resistant phenotype. Impairment of this mechanism contributes to the development of salt-sensitive hypertension.
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Affiliation(s)
- Richard D Wainford
- From the the Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, MA (R.D.W., C.Y.C., J.T.K.); and Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans (R.D.W., C.L.P.).
| | - Casey Y Carmichael
- From the the Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, MA (R.D.W., C.Y.C., J.T.K.); and Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans (R.D.W., C.L.P.)
| | - Crissey L Pascale
- From the the Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, MA (R.D.W., C.Y.C., J.T.K.); and Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans (R.D.W., C.L.P.)
| | - Jill T Kuwabara
- From the the Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, MA (R.D.W., C.Y.C., J.T.K.); and Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans (R.D.W., C.L.P.)
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29
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Veelken R, Schmieder RE. Renal denervation—implications for chronic kidney disease. Nat Rev Nephrol 2014; 10:305-13. [DOI: 10.1038/nrneph.2014.59] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Abstract
PURPOSE This review highlights the physiological mechanisms underlying the neural regulation of the kidney, normally to maintain cardiovascular homeostasis, and in pathophysiological states of hypertension and renal disease. It is relevant because of the demonstration that bilateral renal denervation in different hypertensive groups causes a sustained reduction in blood pressure. RECENT FINDINGS There are patients groups in whom their hypertension is resistant to antihypertensive drugs or with renal diseases in which they are contraindicated. Recently, medical devices have been developed to manipulate the sympathetic nervous system, for example, implantation of carotid sinus nerve stimulating electrodes and ablation of the renal innervation. These approaches have been relatively successful but there remains a lack of understanding of the neural mechanisms impinging on the kidney that regulate long-term control of blood pressure. SUMMARY The observation that bilateral renal nerve ablation can reduce blood pressure represents an important therapeutic milestone. Nonetheless, questions arise as to the underlying mechanisms, the long-term consequences, whether there may be re-innervation over a number of years, or whether some unknown consequence to the denervation may arise. This may point to the development of novel compounds targeted to the innervation of the kidney.
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31
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Stouffer G, DiBona G, Patel A, Kaul P, Hinderliter A. Catheter-based renal denervation in the treatment of resistant hypertension. J Mol Cell Cardiol 2013; 62:18-23. [DOI: 10.1016/j.yjmcc.2013.04.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/19/2013] [Accepted: 04/29/2013] [Indexed: 01/13/2023]
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Veelken R, Mann JFE. Renal sympathetic denervation as antihypertensive therapy--a reappraisal of first results. Nephrol Dial Transplant 2013; 28:2698-701. [PMID: 23945992 DOI: 10.1093/ndt/gft017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Renal sympathetic denervation (RSD) has previously been discussed in this journal. Since then, it has become a common procedure in many countries to use RSD to treat patients with putatively resistant hypertension. In Germany alone, RSD is now routinely used to treat resistant hypertension at the expense of the health-care system. The Germans have established a national registry to systematically and continuously follow up hypertensive patients who have undergone RSD. However, there are concerns because the registry is voluntary and physicians practicing the procedure may not have the accrual of new knowledge regarding the utility of RSD as their primary professional aim. Since the previous editorial on renal denervation, new results have been published. Therefore, it is appropriate to re-evaluate RSD.
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Affiliation(s)
- Roland Veelken
- Medizinische Klinik 4 (Nephrologie und Hypertensiologie), Friedrich Alexander Universitaet Erlangen-Nuernberg, Erlangen-Nuremberg, Germany
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33
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Abstract
NEW FINDINGS What is the topic of this review? Reports that bilateral renal denervation in resistant hypertensive patients results in a long-lasting reduction in blood pressure raise the question of the underlying mechanisms involved and how they may be deranged in pathophysiological states of hypertension and renal failure. What advances does it highlight? The renal sensory afferent nerves and efferent sympathetic nerves work together to exert an important control over extracellular fluid volume, hence the level at which blood pressure is set. This article emphasizes that both the afferent and the efferent renal innervation may contribute to the neural dysregulation of the kidney that occurs in chronic renal disease and resistant hypertension. Autonomic control is central to cardiovascular homeostasis, and this is exerted not only at the level of the heart and blood vessels but also at the kidney. At the kidney, the sympathetic neural regulation of renin release and fluid reabsorption may influence fluid balance and, in the longer term, the level at which blood pressure is set. The role of the renal innervation in the regulation of blood pressure has received renewed attention over the past few years, following the reports that bilateral renal denervation of resistant hypertensive patients resulted in a marked reduction in blood pressure, which has been maintained for several years. Such has been the interest that this approach of renal denervation is being applied in other patient groups with diabetes, obesity and renal failure, with the hope that there may be a sustained reduction in blood pressure as well as the amelioration of some aspects of the metabolic syndrome. However, the factors that come into play to cause the rise in blood pressure in these patient groups, particularly the resistant hypertensive patients, are far from clear. Moreover, the mechanisms leading to the fall in blood pressure following renal denervation of resistant hypertensive patients currently elude our understanding and is therefore an area that requires much more investigation to enhance our insight.
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Affiliation(s)
- Edward J Johns
- * Department of Physiology, Western Gateway Building, University College Cork, Cork, Republic of Ireland.
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Graceli JB, Cicilini MA, Bissoli NS, Abreu GR, Moysés MR. Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney. Braz J Med Biol Res 2013; 46:521-7. [PMID: 23828583 PMCID: PMC3854445 DOI: 10.1590/1414-431x20132666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 03/20/2013] [Indexed: 11/21/2022] Open
Abstract
The maintenance of extracellular Na+ and Cl- concentrations
in mammals depends, at least in part, on renal function. It has been shown that
neural and endocrine mechanisms regulate extracellular fluid volume and
transport of electrolytes along nephrons. Studies of sex hormones and renal
nerves suggested that sex hormones modulate renal function, although this
relationship is not well understood in the kidney. To better understand the role
of these hormones on the effects that renal nerves have on Na+ and
Cl- reabsorption, we studied the effects of renal denervation and
oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol
benzoate (OVE, 2.0 mg·kg-1·day-1, sc) and
progesterone (OVP, 1.7 mg·kg-1·day-1,
sc). We assessed Na+ and Cl- fractional
excretion (FENa+ and FECl-, respectively) and renal and plasma catecholamine release concentrations.
FENa+, FECl-, water intake, urinary flow, and renal and plasma catecholamine release
levels increased in OVX vs control rats. These effects were
reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation
did not alter FENa+, FECl-, water intake, or urinary flow values vs controls.
However, the renal catecholamine release level was decreased in the OVP
(236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2;
ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased
renal catecholamine release levels compared to either treatment alone. OVE
normalized and OVP reduced renal catecholamine release levels, and the effects
on plasma catecholamine release levels were reversed by ODE and ODP replacement
in OD. These data suggest that progesterone may influence catecholamine release
levels by renal innervation and that there are complex interactions among renal
nerves, estrogen, and progesterone in the modulation of renal function.
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Affiliation(s)
- J B Graceli
- Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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Mulder J, Hökfelt T, Knuepfer MM, Kopp UC. Renal sensory and sympathetic nerves reinnervate the kidney in a similar time-dependent fashion after renal denervation in rats. Am J Physiol Regul Integr Comp Physiol 2013; 304:R675-82. [PMID: 23408032 DOI: 10.1152/ajpregu.00599.2012] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Efferent renal sympathetic nerves reinnervate the kidney after renal denervation in animals and humans. Therefore, the long-term reduction in arterial pressure following renal denervation in drug-resistant hypertensive patients has been attributed to lack of afferent renal sensory reinnervation. However, afferent sensory reinnervation of any organ, including the kidney, is an understudied question. Therefore, we analyzed the time course of sympathetic and sensory reinnervation at multiple time points (1, 4, and 5 days and 1, 2, 3, 4, 6, 9, and 12 wk) after renal denervation in normal Sprague-Dawley rats. Sympathetic and sensory innervation in the innervated and contralateral denervated kidney was determined as optical density (ImageJ) of the sympathetic and sensory nerves identified by immunohistochemistry using antibodies against markers for sympathetic nerves [neuropeptide Y (NPY) and tyrosine hydroxylase (TH)] and sensory nerves [substance P and calcitonin gene-related peptide (CGRP)]. In denervated kidneys, the optical density of NPY-immunoreactive (ir) fibers in the renal cortex and substance P-ir fibers in the pelvic wall was 6, 39, and 100% and 8, 47, and 100%, respectively, of that in the contralateral innervated kidney at 4 days, 4 wk, and 12 wk after denervation. Linear regression analysis of the optical density of the ratio of the denervated/innervated kidney versus time yielded similar intercept and slope values for NPY-ir, TH-ir, substance P-ir, and CGRP-ir fibers (all R(2) > 0.76). In conclusion, in normotensive rats, reinnervation of the renal sensory nerves occurs over the same time course as reinnervation of the renal sympathetic nerves, both being complete at 9 to 12 wk following renal denervation.
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Affiliation(s)
- Jan Mulder
- Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
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Freisinger W, Schatz J, Ditting T, Lampert A, Heinlein S, Lale N, Schmieder R, Veelken R. Sensory renal innervation: a kidney-specific firing activity due to a unique expression pattern of voltage-gated sodium channels? Am J Physiol Renal Physiol 2013; 304:F491-7. [PMID: 23283993 DOI: 10.1152/ajprenal.00011.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sensory neurons with afferent axons from the kidney are extraordinary in their response to electrical stimulation. More than 50% exhibit a tonic firing pattern, i.e., sustained action potential firing throughout depolarizing, pointing to an increased excitability, whereas nonrenal neurons show mainly a phasic response, i.e., less than five action potentials. Here we investigated whether these peculiar firing characteristics of renal afferent neurons are due to differences in the expression of voltage-gated sodium channels (Navs). Dorsal root ganglion (DRG) neurons from rats (Th11-L2) were recorded by the current-clamp technique and distinguished as "tonic" or "phasic." In voltage-clamp recordings, Navs were characterized by their tetrodotoxoxin (TTX) sensitivity, and their molecular identity was revealed by RT-PCR. The firing pattern of 66 DRG neurons (41 renal and 25 nonrenal) was investigated. Renal neurons exhibited more often a tonic firing pattern (56.1 vs. 12%). Tonic neurons showed a more positive threshold (-21.75 ± 1.43 vs.-29.33 ± 1.63 mV; P < 0.05), a higher overshoot (56.74 [53.6-60.96] vs. 46.79 mV [38.63-54.75]; P < 0.05) and longer action potential duration (4.61 [4.15-5.85] vs. 3.35 ms [2.12-5.67]; P < 0.05). These findings point to an increased presence of the TTX-resistant Navs 1.8 and 1.9. Furthermore, tonic neurons exhibited a relatively higher portion of TTX-resistant sodium currents. Interestingly, mRNA expression of TTX-resistant sodium channels was significantly increased in renal, predominantly tonic, DRG neurons. Hence, under physiological conditions, renal sensory neurons exhibit predominantly a firing pattern associated with higher excitability. Our findings support that this is due to an increased expression and activation of TTX-resistant Navs.
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Affiliation(s)
- Wolfgang Freisinger
- Dept. of Medicine 4, Univ. of Erlangen-Nürnberg, Loschgestraβe 8, 91054 Erlangen, Germany.
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Abstract
Substance P (SP), a neurokinin-1 receptor (NK-1R) agonist, is mainly produced and stored in primary sensory nerves and, upon its release, participates in cardiovascular and renal functional regulation. This study tests the hypothesis that activation of the NK-1Rs by SP occurs during hypertension induced by deoxycorticosterone (DOCA)-salt treatment, which contributes to renal injury in this model. C57BL/6 mice were subjected to uninephrectomy and DOCA-salt treatment in the presence or absence of administration of selective NK-1 antagonists, L-733,060 (20 mg/kg·d, ip) or RP-67580 (8 mg/kg·d, ip). Five weeks after the treatment, mean arterial pressure determined by the telemetry system increased in DOCA-salt mice but without difference between NK-1R antagonist-treated or NK-1R antagonist-untreated DOCA-salt groups. Plasma SP levels were increased in DOCA-salt compared with control mice (P < 0.05). Renal hypertrophy and increased urinary 8-isoprostane and albumin excretion were observed in DOCA-salt compared with control mice (P < 0.05). Periodic acid-Schiff and Masson's trichrome staining showed more severe glomerulosclerosis and tubulointerstitial injury in the renal cortex in DOCA-salt compared with control mice, respectively (P < 0.05). Hydroxyproline assay and F4/80-staining showed that renal collagen levels and interstitial monocyte/macrophage infiltration were greater in DOCA-salt compared with control mice, respectively (P < 0.05). Blockade of the NK-1R with L-733,060 or RP-67580 in DOCA-salt mice suppressed increments in urinary 8-isoprostane and albumin excretion, interstitial monocyte/macrophage infiltration, and glomerulosclerosis and tubulointerstitial injury and fibrosis (P < 0.05). Thus, our data show that blockade of the NK-1Rs alleviates renal functional and tissue injury in the absence of alteration in blood pressure in DOCA-salt-hypertensive mice. The results suggest that elevated SP levels during DOCA-salt hypertension play a significant role contributing to renal damage possibly via enhancing oxidative stress and macrophage infiltration of the kidney.
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Affiliation(s)
- Youping Wang
- Central Laboratory and Division of Cardiology, First Affiliated Hospital, Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China
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Wang Y, Wang DH. Role of the transient receptor potential vanilloid type 1 channel in renal inflammation induced by lipopolysaccharide in mice. Am J Physiol Regul Integr Comp Physiol 2012; 304:R1-9. [PMID: 23152109 DOI: 10.1152/ajpregu.00163.2012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
To determine the role of the transient receptor potential vanilloid type 1 (TRPV1) channel in the regulation of renal inflammation, lipopolysaccharide (LPS, 3 mg/kg) was intraperitoneally injected into wild-type (WT) and TRPV1-null mutant (TRPV1(-/-)) mice. The kidney and serum were collected 6 or 24 h after LPS injection for morphological analysis and proinflammatory cytokine assay. LPS injection led to a similar degree of transient hypotension and bradycardia in WT and TRPV1(-/-) mice determined by a telemetry system. LPS administration caused parenchymal red blood cell congestion and fading of intact glomerular structure in TRPV1(-/-) compared with WT mice. Serum creatinine levels were higher 24 h after LPS injection in TRPV1(-/-) than in WT mice. Neutrophil and macrophage infiltration in the kidneys was greater 6 h for the former and 24 h for both after LPS injection in TRPV1(-/-) than in WT mice. Serum cytokine levels including tumor necrosis factor (TNF)-α, IL-1β, and IL-6 were higher 6 h after LPS injection in TRPV1(-/-) compared with WT mice. Likewise, renal chemokine levels including keratinocyte-derived chemokines and macrophage inflammatory protein were higher 6 h after LPS injection in TRPV1(-/-) than in WT mice. Renal VCAM-1 and ICAM-1 expression was further elevated 6 h for the former and 24 h for the latter after LPS injection in TRPV1(-/-) than in WT mice. Renal nuclear factor-κB (NF-κB) activity was further increased 6 h after LPS injection in TRPV1(-/-) compared with WT mice. Pharmacological blockade TRPV1 in WT mice showed aggravated renal and serum inflammatory responses resembling that of TRPV1(-/-) mice. Thus TRPV1 gene ablation exacerbates LPS-induced renal tissue and function injury, including aggravated renal neutrophil and macrophage infiltration, chemokine and adhesion molecule levels, and glomerular hypercellularity accompanying with further increased serum creatinine and cytokine levels. These results indicate that TRPV1 is activated during LPS challenge, which may constitute a protect mechanism against LPS-induced renal injury via reducing renal inflammatory responses.
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Affiliation(s)
- Youping Wang
- Central Laboratory and Division of Cardiology, First Affiliated Hospital, Henan University of Traditional Chinese Medicine, Zhengzhou, China
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Fujita M, Ando K, Kawarazaki H, Kawarasaki C, Muraoka K, Ohtsu H, Shimizu H, Fujita T. Sympathoexcitation by brain oxidative stress mediates arterial pressure elevation in salt-induced chronic kidney disease. Hypertension 2011; 59:105-12. [PMID: 22083162 DOI: 10.1161/hypertensionaha.111.182923] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypertension is very prevalent in chronic kidney disease and critical for its prognosis. Sympathoexcitation and oxidative stress have been demonstrated to be involved in chronic kidney disease. We have shown previously that sympathoexcitation by brain oxidative stress mediates arterial pressure elevation in the salt-sensitive hypertension model, Dahl salt-sensitive rats. Thus, we investigated whether sympathoexcitation by excessive brain oxidative stress could contribute to arterial pressure elevation in salt-induced chronic kidney disease model rats. Young (3-week-old) male Sprague-Dawley rats were randomly assigned to a uninephrectomy or sham operation and then subjected to either a normal salt (0.5%) or high-salt (8.0%) diet for 4 weeks. The young salt-loaded uninephrectomized rats exhibited sympathoexcitation, hypertension, and renal injury, proteinuria and global glomerulosclerosis together with tubulointerstitial damage. Under urethane anesthesia and artificial ventilation, renal sympathetic nerve activity, arterial pressure, and heart rate decreased to a greater degree in the salt-loaded uninephrectomized rats than in the nonsalt-loaded uninephrectomized rats and the salt-loaded or nonsalt-loaded sham-operated rats, when Tempol, a membrane-permeable superoxide dismutase mimetic, was infused acutely into the lateral cerebral ventricle. Oxidative stress in the hypothalamus, measured by lucigenin chemiluminescence, was also significantly greater. Furthermore, in the salt-loaded uninephrectomized rats, antioxidant treatment with chronic intracerebroventricular Tempol decreased sympathetic nerve activity and arterial pressure, which, in turn, led to a decrease in renal damage. Similar effects were elicited by treatment with oral moxonidine, the central sympatholytic agent. In conclusion, sympathoexcitation by brain oxidative stress may mediate arterial pressure elevation in salt-induced chronic kidney disease.
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Affiliation(s)
- Megumi Fujita
- Department of Nephrology and Endocrinology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
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Ditting T, Linz P, Freisinger W, Heinlein S, Reeh PW, Fiedler C, Siegel K, Scrogin KE, Neuhuber W, Veelken R. Norepinephrine reduces ω-conotoxin-sensitive Ca2+ currents in renal afferent neurons in rats. Am J Physiol Renal Physiol 2011; 302:F350-7. [PMID: 22049399 DOI: 10.1152/ajprenal.00681.2010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sympathetic efferent and peptidergic afferent renal nerves likely influence hypertensive and inflammatory kidney disease. Our recent investigation with confocal microscopy revealed that in the kidney sympathetic nerve endings are colocalized with afferent nerve fibers (Ditting T, Tiegs G, Rodionova K, Reeh PW, Neuhuber W, Freisinger W, Veelken R. Am J Physiol Renal Physiol 297: F1427-F1434, 2009; Veelken R, Vogel EM, Hilgers K, Amman K, Hartner A, Sass G, Neuhuber W, Tiegs G. J Am Soc Nephrol 19: 1371-1378, 2008). However, it is not known whether renal afferent nerves are influenced by sympathetic nerve activity. We tested the hypothesis that norepinephrine (NE) influences voltage-gated Ca(2+) channel currents in cultured renal dorsal root ganglion (DRG) neurons, i.e., the first-order neuron of the renal afferent pathway. DRG neurons (T11-L2) retrogradely labeled from the kidney and subsequently cultured, were investigated by whole-cell patch clamp. Voltage-gated calcium channels (VGCC) were investigated by voltage ramps (-100 to +80 mV, 300 ms, every 20 s). NE and appropriate adrenergic receptor antagonists were administered by microperfusion. NE (20 μM) reduced VGCC-mediated currents by 10.4 ± 3.0% (P < 0.01). This reduction was abolished by the α-adrenoreceptor inhibitor phentolamine and the α(2)-adrenoceptor antagonist yohimbine. The β-adrenoreceptor antagonist propranolol and the α(1)-adrenoceptor antagonist prazosin had no effect. The inhibitory effect of NE was abolished when N-type currents were blocked by ω-conotoxin GVIA, but was unaffected by other specific Ca(2+) channel inhibitors (ω-agatoxin IVA; nimodipine). Confocal microscopy revealed sympathetic innervation of DRGs and confirmed colocalization of afferent and efferent fibers within in the kidney. Hence NE released from intrarenal sympathetic nerve endings, or sympathetic fibers within the DRGs, or even circulating catecholamines, may influence the activity of peptidergic afferent nerve fibers through N-type Ca(2+) channels via an α(2)-adrenoceptor-dependent mechanism. However, the exact site and the functional role of this interaction remains to be elucidated.
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Affiliation(s)
- Tilmann Ditting
- Dept. of Internal Medicine 4, Nephrology and Hypertension, Erlangen, Germany.
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Affiliation(s)
- Ulla C. Kopp
- University of Iowa Carver College of Medicine and Department of Veterans Affairs Medical Center
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Katholi RE, Rocha-Singh KJ, Goswami NJ, Sobotka PA. Renal nerves in the maintenance of hypertension: a potential therapeutic target. Curr Hypertens Rep 2011; 12:196-204. [PMID: 20424950 DOI: 10.1007/s11906-010-0108-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Renal sympathetic efferent and afferent nerves, which lie within and immediately adjacent to the wall of the renal arteries, contribute to the maintenance of hypertension. Because the causative factors of hypertension change over time, denervation of both efferent and afferent renal nerves should result in long-term attenuation of hypertension. The importance of the renal nerves in hypertensive patients can now be defined with the novel development of percutaneous, minimally invasive renal denervation from within the renal artery using radiofrequency energy as a therapeutic strategy. Studies thus far show that catheter-based renal denervation in patients with resistant essential hypertension lowers systolic blood pressure 27 mm Hg by 12 months, with the estimated glomerular filtration rate remaining stable. The decrease in arterial pressure after renal denervation is associated with decreased peripheral sympathetic nervous system activity, suggesting that the kidney is a source of significant central sympathetic outflow via afferent renal nerve activity.
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Affiliation(s)
- Richard E Katholi
- Prairie Education and Research Cooperative, 317 North 5th Street, Springfield, IL 62701, USA.
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Boer PA, Rossi CDL, Mesquita FF, Gontijo JAR. Early potential impairment of renal sensory nerves in streptozotocin-induced diabetic rats: role of neurokinin receptors. Nephrol Dial Transplant 2011; 26:823-832. [DOI: 10.1093/ndt/gfq512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Kohan DE, Rossi NF, Inscho EW, Pollock DM. Regulation of blood pressure and salt homeostasis by endothelin. Physiol Rev 2011; 91:1-77. [PMID: 21248162 DOI: 10.1152/physrev.00060.2009] [Citation(s) in RCA: 276] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endothelin (ET) peptides and their receptors are intimately involved in the physiological control of systemic blood pressure and body Na homeostasis, exerting these effects through alterations in a host of circulating and local factors. Hormonal systems affected by ET include natriuretic peptides, aldosterone, catecholamines, and angiotensin. ET also directly regulates cardiac output, central and peripheral nervous system activity, renal Na and water excretion, systemic vascular resistance, and venous capacitance. ET regulation of these systems is often complex, sometimes involving opposing actions depending on which receptor isoform is activated, which cells are affected, and what other prevailing factors exist. A detailed understanding of this system is important; disordered regulation of the ET system is strongly associated with hypertension and dysregulated extracellular fluid volume homeostasis. In addition, ET receptor antagonists are being increasingly used for the treatment of a variety of diseases; while demonstrating benefit, these agents also have adverse effects on fluid retention that may substantially limit their clinical utility. This review provides a detailed analysis of how the ET system is involved in the control of blood pressure and Na homeostasis, focusing primarily on physiological regulation with some discussion of the role of the ET system in hypertension.
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Affiliation(s)
- Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
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TRPV1: A Therapy Target That Attracts the Pharmaceutical Interests. TRANSIENT RECEPTOR POTENTIAL CHANNELS 2011; 704:637-65. [DOI: 10.1007/978-94-007-0265-3_34] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Kopp UC, Cicha MZ, Smith LA, Ruohonen S, Scheinin M, Fritz N, Hökfelt T. Dietary sodium modulates the interaction between efferent and afferent renal nerve activity by altering activation of α2-adrenoceptors on renal sensory nerves. Am J Physiol Regul Integr Comp Physiol 2010; 300:R298-310. [PMID: 21106912 DOI: 10.1152/ajpregu.00469.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Activation of efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which then reflexively decreases ERSNA via activation of the renorenal reflexes to maintain low ERSNA. The ERSNA-ARNA interaction is mediated by norepinephrine (NE) that increases and decreases ARNA by activation of renal α(1)-and α(2)-adrenoceptors (AR), respectively. The ERSNA-induced increases in ARNA are suppressed during a low-sodium (2,470 ± 770% s) and enhanced during a high-sodium diet (5,670 ± 1,260% s). We examined the role of α(2)-AR in modulating the responsiveness of renal sensory nerves during low- and high-sodium diets. Immunohistochemical analysis suggested the presence of α(2A)-AR and α(2C)-AR subtypes on renal sensory nerves. During the low-sodium diet, renal pelvic administration of the α(2)-AR antagonist rauwolscine or the AT1 receptor antagonist losartan alone failed to alter the ARNA responses to reflex increases in ERSNA. Likewise, renal pelvic release of substance P produced by 250 pM NE (from 8.0 ± 1.3 to 8.5 ± 1.6 pg/min) was not affected by rauwolscine or losartan alone. However, rauwolscine+losartan enhanced the ARNA responses to reflex increases in ERSNA (4,680 ± 1,240%·s), and renal pelvic release of substance P by 250 pM NE, from 8.3 ± 0.6 to 14.2 ± 0.8 pg/min. During a high-sodium diet, rauwolscine had no effect on the ARNA response to reflex increases in ERSNA or renal pelvic release of substance P produced by NE. Losartan was not examined because of low endogenous ANG II levels in renal pelvic tissue during a high-sodium diet. Increased activation of α(2)-AR contributes to the reduced interaction between ERSNA and ARNA during low-sodium intake, whereas no/minimal activation of α(2)-AR contributes to the enhanced ERSNA-ARNA interaction under conditions of high sodium intake.
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Affiliation(s)
- Ulla C Kopp
- Dept. of Internal Medicine, Department of Veterans Affairs Medical Center, Bldg. 41, Highway 6W, Iowa City, IA 52246, USA.
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Doumas M, Faselis C, Papademetriou V. Renal sympathetic denervation and systemic hypertension. Am J Cardiol 2010; 105:570-6. [PMID: 20152255 DOI: 10.1016/j.amjcard.2009.10.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/07/2009] [Accepted: 10/07/2009] [Indexed: 02/08/2023]
Abstract
Hypertension represents a major health problem, with an appalling annual toll. Despite the plethora of antihypertensive drugs, hypertension remains resistant in a considerable number of patients, thus creating the need for alternative strategies, including interventional approaches. Recently, renal sympathetic denervation (RSD) using a very elegant, state-of-the-art technique (percutaneous, catheter-based radiofrequency ablation) was shown to be beneficial in patients with resistant hypertension. The pathophysiology of kidney function justifies the use of RSD in the treatment of hypertension. Data from older studies have shown that sympathectomy has efficiently lowered blood pressure and prolonged the life expectancy of patients with hypertension, but at considerable cost. RSD is devoid of the adverse effects of sympathectomy because of its localized nature, is minimally invasive, and provides short procedural and recovery times. In conclusion, this review outlines the pathophysiologic background of RSD, describes the past and the present of this interventional approach, and considers several future potential applications.
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DiBona GF, Esler M. Translational medicine: the antihypertensive effect of renal denervation. Am J Physiol Regul Integr Comp Physiol 2009; 298:R245-53. [PMID: 19955493 DOI: 10.1152/ajpregu.00647.2009] [Citation(s) in RCA: 282] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Translational medicine is concerned with the translation of research discoveries into clinical applications for the prevention, diagnosis, and treatment of human diseases. Here we briefly review the research concerning the role of the renal sympathetic nerves (efferent and afferent) in the control of renal function, with particular reference to hypertension. The accumulated evidence is compelling for a primary role of the renal innervation in the pathogenesis of hypertension. These research discoveries led to the development of a catheter-based procedure for renal denervation in human subjects. A proof-of-principle study in patients with hypertension resistant to conventional therapy has demonstrated that the procedure is safe and produces renal denervation with sustained lowering of arterial pressure.
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Affiliation(s)
- Gerald F DiBona
- University of Iowa Carver College of Medicine and Veterans Administration Medical Center, Iowa City, Iowa, USA.
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Yemane H, Busauskas M, Burris SK, Knuepfer MM. Neurohumoral mechanisms in deoxycorticosterone acetate (DOCA)-salt hypertension in rats. Exp Physiol 2009; 95:51-5. [PMID: 19700514 DOI: 10.1113/expphysiol.2008.046334] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This brief review describes the role of neural and non-neural mechanisms during different phases of deoxycorticosterone acetate (DOCA)-salt hypertension. There are contradictory data for and against a role of the sympathetic nervous system and neurohumoral agents, including endothelin and vasopressin. Elucidating the factors responsible for DOCA-salt hypertension will be helpful in understanding the causes of hypertension resulting from hypervolaemia, hyperaldosteronism and high salt intake.
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Affiliation(s)
- Henok Yemane
- Department of Pharmacological and Physiological Science, St Louis University School of Medicine, 1402 South Grand Boulevard, St Louis, MO 63104, USA
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