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Pontes RB, Nishi EE, Crajoinas RO, Milanez MIO, Girardi ACC, Campos RR, Bergamaschi CT. Relative Contribution of Blood Pressure and Renal Sympathetic Nerve Activity to Proximal Tubular Sodium Reabsorption via NHE3 Activity. Int J Mol Sci 2022; 24:ijms24010349. [PMID: 36613793 PMCID: PMC9820392 DOI: 10.3390/ijms24010349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
We examined the effects of an acute increase in blood pressure (BP) and renal sympathetic nerve activity (rSNA) induced by bicuculline (Bic) injection in the paraventricular nucleus of hypothalamus (PVN) or the effects of a selective increase in rSNA induced by renal nerve stimulation (RNS) on the renal excretion of sodium and water and its effect on sodium-hydrogen exchanger 3 (NHE3) activity. Uninephrectomized anesthetized male Wistar rats were divided into three groups: (1) Sham; (2) Bic PVN: (3) RNS + Bic injection into the PVN. BP and rSNA were recorded, and urine was collected prior and after the interventions in all groups. RNS decreased sodium (58%) and water excretion (53%) independently of BP changes (p < 0.05). However, after Bic injection in the PVN during RNS stimulation, the BP and rSNA increased by 30% and 60% (p < 0.05), respectively, diuresis (5-fold) and natriuresis (2.3-fold) were increased (p < 0.05), and NHE3 activity was significantly reduced, independently of glomerular filtration rate changes. Thus, an acute increase in the BP overcomes RNS, leading to diuresis, natriuresis, and NHE3 activity inhibition.
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Affiliation(s)
- Roberto B. Pontes
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Erika E. Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Renato O. Crajoinas
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo 01246-903, Brazil
| | - Maycon I. O. Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Adriana C. C. Girardi
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo 01246-903, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Cassia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
- Correspondence:
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Milanez MIO, Nishi EE, Mendes R, Rocha AA, Bergamaschi CT, Campos RR. Renal sympathetic activation triggered by the rostral ventrolateral medulla is dependent of spinal cord AT1 receptors in Goldblatt hypertensive rats. Peptides 2021; 146:170660. [PMID: 34571055 DOI: 10.1016/j.peptides.2021.170660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/30/2021] [Accepted: 09/22/2021] [Indexed: 11/20/2022]
Abstract
Spinal cord neurons contribute to elevated sympathetic vasomotor activity in renovascular hypertension (2K1C), particularly, increased actions of angiotensin II. However, the origin of these spinal angiotensinergic inputs remains unclear. The present study aimed to investigate the role of spinal angiotensin II type 1 receptor (AT1) receptors in the sympathoexcitatory responses evoked by the activation of the rostral ventrolateral medulla (RVLM) in control and 2K1C Goldblatt rats. Hypertension was induced by clipping of the left renal artery. After 6 weeks, a catheter (PE-10) filled with losartan was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anesthetized rats. The effects of glutamate microinjection into the RVLM on blood pressure (BP), heart rate (HR), and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated in the presence or absence of spinal AT1 blockade. Tachycardic, pressor, and renal sympathoexcitatory effects caused by RVLM activation were significantly blunted by losartan in 2K1C rats, but not in control rats. However, no differences were found in the gene expression of angiotensin-converting enzyme, angiotensinogen, and renin in the spinal cord segments between the groups. In conclusion, acute sympathoexcitation induced by RVLM activation is dependent on the spinal AT1 receptor in Goldblatt, but not in control, rats. The involvement of other central cardiovascular nuclei in spinal angiotensinergic actions, as well as the source of angiotensin II, remains to be determined in the Goldblatt model.
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Affiliation(s)
- Maycon I O Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Rodrigo Mendes
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Antônio A Rocha
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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Garcia ML, Milanez MIO, Nishi EE, Sato AYS, Carvalho PM, Nogueira FN, Campos RR, Oyama LM, Bergamaschi CT. Retroperitoneal adipose tissue denervation improves cardiometabolic and autonomic dysfunction in a high fat diet model. Life Sci 2021; 283:119841. [PMID: 34298036 DOI: 10.1016/j.lfs.2021.119841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022]
Abstract
Sympathetic vasomotor overactivity is a major feature leading to the cardiovascular dysfunction related to obesity. Considering that the retroperitoneal white adipose tissue (rWAT) is an important fat visceral depot and receives intense sympathetic and afferent innervations, the present study aimed to evaluate the effects evoked by bilateral rWAT denervation in obese rats. Male Wistar rats were fed with HFD for 8 consecutive weeks and rWAT denervation was performed at the 6th week. Arterial pressure, splanchnic and renal sympathetic vasomotor nerve activities were assessed and inflammation and the components of the renin -angiotensin system were evaluated in different white adipose tissue depots. HFD animals presented higher serum levels of leptin and glucose, an increase in arterial pressure and splanchnic sympathetic nerve activity; rWAT denervation, normalized these parameters. Pro-inflammatory cytokines levels were significantly increased, as well as RAAS gene expression in WAT of HFD animals; rWAT denervation significantly attenuated these changes. In conclusion, HFD promotes vasomotor sympathetic overactivation and inflammation with repercussions on the cardiovascular system. In conclusion, the neural communication between WAT and the brain is fundamental to trigger sympathetic vasomotor activation and this pathway is a possible new therapeutic target to treat obesity-associated cardiovascular dysfunction.
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Affiliation(s)
- Michelle L Garcia
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Maycon I O Milanez
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Alex Y S Sato
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Polliane M Carvalho
- Department of Biomaterials and Oral Biology, Faculdade de Odontologia, Universidade de São Paulo, Brazil
| | - Fernando N Nogueira
- Department of Biomaterials and Oral Biology, Faculdade de Odontologia, Universidade de São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Lila M Oyama
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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Veiga AC, Milanez MIO, Campos RR, Bergamaschi CT, Nishi EE. The involvement of renal afferents in the maintenance of cardiorenal diseases. Am J Physiol Regul Integr Comp Physiol 2021; 320:R88-R93. [PMID: 33146555 DOI: 10.1152/ajpregu.00225.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elevated sympathetic vasomotor activity is a common feature of cardiorenal diseases. Therefore, the sympathetic nervous system is an important therapeutic target, particularly the fibers innervating the kidneys. In fact, renal denervation has been applied clinically and shown promising results in patients with hypertension and chronic kidney disease. However, the underlying mechanisms involved in the cardiorenal protection induced by renal denervation have not yet been fully clarified. This mini-review highlights historical and recent aspects related to the role of renal sensory fibers in the control of cardiorenal function under normal conditions and in experimental models of cardiovascular disease. Results have demonstrated that alterations in renal sensory function participate in the maintenance of elevated sympathetic vasomotor activity and cardiorenal changes; as such, renal sensory fibers may be a potential therapeutic target for the treatment of cardiorenal diseases. Although it has not yet been applied in clinical practice, selective afferent renal denervation may be promising, since such an approach maintains efferent activity and can provide more refined control of renal function compared with total renal denervation. However, more studies are needed to understand the mechanisms by which renal afferents partially contribute to such changes, in addition to the need to evaluate the safety and advantages of the approach for application in the clinical practice.
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Affiliation(s)
- Amanda C Veiga
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Maycon I O Milanez
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Cassia T Bergamaschi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, Sao Paulo, Brazil
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Milanez MIO, Veiga AC, Martins BS, Pontes RB, Bergamaschi CT, Campos RR, Nishi EE. Renal Sensory Activity Regulates the γ-Aminobutyric Acidergic Inputs to the Paraventricular Nucleus of the Hypothalamus in Goldblatt Hypertension. Front Physiol 2020; 11:601237. [PMID: 33384613 PMCID: PMC7769809 DOI: 10.3389/fphys.2020.601237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 12/27/2022] Open
Abstract
Renal sensory activity is centrally integrated within brain nuclei involved in the control of cardiovascular function, suggesting that renal afferents regulate basal and reflex sympathetic vasomotor activity. Evidence has shown that renal deafferentation (DAx) evokes a hypotensive and sympathoinhibitory effect in experimental models of cardiovascular diseases; however, the underlying mechanisms involved in this phenomenon need to be clarified, especially those related to central aspects. We aimed to investigate the role of renal afferents in the control of γ-aminobutyric acid (GABA)ergic inputs to the paraventricular nucleus (PVN) of the hypothalamus in renovascular hypertensive (2K1C) rats and their influence in the regulation of cardiovascular function. Hypertension was induced by clipping the left renal artery. After 4 weeks, renal DAx was performed by exposing the left renal nerve to a 33 mM capsaicin solution for 15 min. After 2 weeks of DAx, microinjection of muscimol into the PVN was performed in order to evaluate the influence of GABAergic activity in the PVN and its contribution to the control of renal sympathetic nerve activity (rSNA) and blood pressure (BP). Muscimol microinjected into the PVN triggered a higher drop in BP and rSNA in the 2K1C rats and renal DAx mitigated these responses. These results suggest that renal afferents are involved in the GABAergic changes found in the PVN of 2K1C rats. Although the functional significance of this phenomenon needs to be clarified, it is reasonable to speculate that GABAergic alterations occur to mitigate microglia activation-induced sympathoexcitation in the PVN of 2K1C rats.
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Affiliation(s)
- Maycon I O Milanez
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Amanda C Veiga
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Beatriz S Martins
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Roberto B Pontes
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cassia T Bergamaschi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Milanez MIO, Nishi EE, Bergamaschi CT, Campos RR. Role of spinal neurons in the maintenance of elevated sympathetic activity: a novel therapeutic target? Am J Physiol Regul Integr Comp Physiol 2020; 319:R282-R287. [DOI: 10.1152/ajpregu.00122.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The control of sympathetic vasomotor activity involves a complex network within the brain and spinal circuits. An extensive range of studies has indicated that sympathoexcitation is a common feature in several cardiovascular diseases and that strategies to reduce sympathetic vasomotor overactivity in such conditions can be beneficial. In the present mini-review, we present evidence supporting the spinal cord as a potential therapeutic target to mitigate sympathetic vasomotor overactivity in cardiovascular diseases, focusing mainly on the actions of spinal angiotensin II on the control of sympathetic preganglionic neuronal activity.
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Affiliation(s)
- Maycon I. O. Milanez
- Cardiovascular Physiology Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil
| | - Erika E. Nishi
- Cardiovascular Physiology Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil
| | - Cássia T. Bergamaschi
- Cardiovascular Physiology Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil
| | - Ruy R. Campos
- Cardiovascular Physiology Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil
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Zambrano LI, Pontes RB, Garcia ML, Nishi EE, Nogueira FN, Higa EMS, Cespedes JG, Bergamaschi CT, Campos RR. Pattern of sympathetic vasomotor activity in a model of hypertension induced by nitric oxide synthase blockade. Physiol Rep 2020; 7:e14183. [PMID: 31325242 PMCID: PMC6642275 DOI: 10.14814/phy2.14183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 12/12/2022] Open
Abstract
We aimed to investigate the effects of nitric oxide (NO) synthesis inhibition by NO synthase inhibitor N‐nitro‐L‐arginine‐methyl ester (L‐NAME) treatment on the sympathetic vasomotor nerve activity (SNA) on two sympathetic vasomotor nerves, the renal and splanchnic. NO plasma level and systemic oxidative stress were assessed. Hypertension was induced by L‐NAME (20 mg/kg per day, by gavage, for seven consecutive days) in male Wistar rats. At the end of the treatment, blood pressure, heart rate, arterial baroreflex sensitivity, renal SNA (rSNA), and splanchnic SNA (sSNA) were assessed in urethane anesthetized rats. L‐NAME‐treated rats presented increased blood pressure (152 ± 2 mmHg, n = 17) compared to the control group (101 ± 2 mmHg, n = 15). Both rSNA (147 ± 10, n = 15 vs. 114 ± 5 Spikes/s, n = 9) and sSNA (137 ± 13, n = 14 vs. 74 ± 13 spikes/s, n = 9) were significantly increased in the L‐NAME‐treated compared to the control group. A differential response on baroreflex sensitivity was found, with a significant reduction for rSNA but not for sSNA arterial baroreceptor sensitivity in L‐NAME‐treated rats. The adjusted regression model revealed that the reduction of systemic NO levels partially explains the variation in sSNA and blood pressure, but not rSNA. Taken together, our data show that hypertension induced by NO synthase blockade is characterized by increased SNA to the rSNA and sSNA. In addition, we found that the rats that had the greatest reduction in NO levels in plasma by L‐NAME were those that developed higher blood pressure levels. The reduction in the NO level partially explains the variations in sSNA but not in rSNA.
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Affiliation(s)
- Lysien I Zambrano
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil.,Department of Morphology, School of Medical Sciences, National Autonomous University of Honduras, Tegucigalpa, Honduras
| | - Roberto B Pontes
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
| | - Michelle L Garcia
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
| | - Fernando N Nogueira
- Departamento de Biomateriais e Biologia Oral, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, Brazil
| | - Elisa M S Higa
- Nephrology Division, Escola Paulista de Medicina Universidade Federal de São Paulo, São Paulo, Brazil
| | - Juliana G Cespedes
- Institute of Science and Technology, Universidade Federal de São Paulo, São Jose dos Campos, Brazil
| | - Cassia T Bergamaschi
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Cardiovascular Division, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
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Milanez MIO, Nishi EE, Rocha AA, Bergamaschi CT, Campos RR. Interaction between angiotensin II and GABA in the spinal cord regulates sympathetic vasomotor activity in Goldblatt hypertension. Neurosci Lett 2020; 728:134976. [PMID: 32304717 DOI: 10.1016/j.neulet.2020.134976] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/17/2020] [Accepted: 04/07/2020] [Indexed: 12/16/2022]
Abstract
Previous studies have been described changes in brain regions contributing to the sympathetic vasomotor overactivity in Goldblatt hypertension (2K1C). Furthermore, changes in the spinal cord are also involved in the cardiovascular and autonomic dysfunction in renovascular hypertension, as intrathecal (i.t.) administration of Losartan (Los) causes a robust hypotensive/sympathoinhibitory response in 2K1C but not in control rats. The present study evaluated the role of spinal γ-aminobutyric acid (GABA)-ergic inputs in the control of sympathetic vasomotor activity in the 2K1C rats. Hypertension was induced by clipping the renal artery. After six weeks, a catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anaesthetized rats. The effects of i.t. injection of bicuculline (Bic) on blood pressure (BP), renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated over 40 consecutive minutes in the presence or absence of spinal AT1 antagonism. I.t. Bic triggered a more intense pressor and sympathoexcitatory response in 2K1C rats, however, these responses were attenuated by previous i.t. Los. No differences in the gene expression of GAD 65 and GABA-A receptors subunits in the spinal cord segments were found. Thus, the sympathoexcitation induced by spinal GABA-A blockade is dependent of local AT1 receptor in 2K1C but not in control rats. Excitatory angiotensinergic inputs to sympathetic preganglionic neurons are tonic controlled by spinal GABAergic actions in Goldblatt hypertension.
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Affiliation(s)
- Maycon I O Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Antônio A Rocha
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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Nishi EE, Ferreira GR, Garcia ML, Campos RR, Bergamaschi CMT. Effects of white adipose tissue denervation on cardiovascular and renal parameters in Wistar rats treated with high‐fat diet. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.08969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Campos RR, Milanez MI, Silva AM, Perry JC, Faber J, Nishi EE, Bergamaschi C. Pattern of sympathetic vasomotor activity induced by GABAergic inhibition in the brain and spinal cord. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.05164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ruy R. Campos
- Escola Paulista de Medicina - Universidade Federal de São Paulo
| | | | | | | | - Jean Faber
- Escola Paulista de Medicina - Universidade Federal de São Paulo
| | - Erika E. Nishi
- Escola Paulista de Medicina - Universidade Federal de São Paulo
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Milanez MIO, Silva AM, Perry JC, Faber J, Nishi EE, Bergamaschi CT, Campos RR. Pattern of sympathetic vasomotor activity induced by GABAergic inhibition in the brain and spinal cord. Pharmacol Rep 2020; 72:67-79. [PMID: 32016845 DOI: 10.1007/s43440-019-00025-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/05/2019] [Accepted: 10/11/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Knowledge of the central areas involved in the control of sympathetic vasomotor activity has advanced in the last few decades. γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammal nervous system, and a microinjection of bicuculline, an antagonist of GABA type A (GABA-A) receptors, into the paraventricular nucleus of the hypothalamus (PVN) alters the pattern of sympathetic activity to the renal, splanchnic and lumbar territories. However, studies are needed to clarify the role of GABAergic inputs in other central areas involved in the sympathetic vasomotor activity. The present work studied the cardiovascular effects evoked by GABAergic antagonism in the PVN, RVLM and spinal cord. METHODS AND RESULTS Bicuculline microinjections (400 pMol in 100 nL) into the PVN and rostral ventrolateral medulla (RVLM) as well as intrathecal administration (1.6 nmol in 2 µL) evoked an increase in blood pressure, heart rate, and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively), inducing a higher coherence between rSNA and sSNA patterns. However, some of these responses were more intense when the GABA-A antagonism was performed in the RVLM than when the GABA-A antagonism was performed in other regions. CONCLUSIONS Administration of bicuculline into the RVLM, PVN and SC induced a similar pattern of renal and splanchnic sympathetic vasomotor burst discharge, characterized by a low-frequency (0.5 Hz) and high-amplitude pattern, despite different blood pressure responses. Thus, the differential control of sympathetic drive to different targets by each region is dependent, in part, on tonic GABAergic inputs.
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Affiliation(s)
- Maycon I O Milanez
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil
| | - Adilson M Silva
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil
| | - Juliana C Perry
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil
| | - Jean Faber
- Department of Neurology and Neurosurgery, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, Ground Floor, CEP 04023-060, São Paulo, SP, Brazil.
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Lopes NR, Milanez MIO, Martins BS, Veiga AC, Ferreira GR, Gomes GN, Girardi AC, Carvalho PM, Nogueira FN, Campos RR, Bergamaschi CT, Nishi EE. Afferent innervation of the ischemic kidney contributes to renal dysfunction in renovascular hypertensive rats. Pflugers Arch 2020; 472:325-334. [PMID: 31925527 DOI: 10.1007/s00424-019-02346-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/27/2019] [Accepted: 12/30/2019] [Indexed: 12/21/2022]
Abstract
The ablation of renal nerves, by destroying both the sympathetic and afferent fibers, has been shown to be effective in lowering blood pressure in resistant hypertensive patients. However, experimental studies have reported that the removal of sympathetic fibers may lead to side effects, such as the impairment of compensatory cardiorenal responses during a hemodynamic challenge. In the present study, we evaluated the effects of the selective removal of renal afferent fibers on arterial hypertension, renal sympathetic nerve activity, and renal changes in a model of renovascular hypertension. After 4 weeks of clipping the left renal artery, afferent renal denervation (ARD) was performed by exposing the left renal nerve to a 33 mM capsaicin solution for 15 min. After 2 weeks of ARD, we found reduced MAP (~ 18%) and sympathoexcitation to both the ischemic and contralateral kidneys in the hypertensive group. Moreover, a reduction in reactive oxygen species was observed in the ischemic (76%) and contralateral (27%) kidneys in the 2K1C group. In addition, ARD normalized renal function markers and proteinuria and podocin in the contralateral kidney. Taken altogether, we show that the selective removal of afferent fibers is an effective method to reduce MAP and improve renal changes without compromising the function of renal sympathetic fibers in the 2K1C model. Renal afferent nerves may be a new target in neurogenic hypertension and renal dysfunction.
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Affiliation(s)
- Nathalia R Lopes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Maycon I O Milanez
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Beatriz S Martins
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Amanda C Veiga
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Giovanna R Ferreira
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Guiomar N Gomes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Adriana C Girardi
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Polliane M Carvalho
- Department of Biomaterials and Oral Biology, Dentistry Faculty, Universidade de São Paulo, São Paulo, Brazil
| | - Fernando N Nogueira
- Department of Biomaterials and Oral Biology, Dentistry Faculty, Universidade de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil.
- Cardiovascular and Respiratory Physiology Division, Department of Physiology, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu, 862, São Paulo, SP, 04023-060, Brazil.
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13
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Milanez MIO, Martins GR, Nishi EE, Bergamaschi CT, Campos RR. Differential sympathetic vasomotor control by spinal AT 1 and V1a receptors in the acute phase of hemorrhagic shock. Eur J Pharmacol 2020; 866:172819. [PMID: 31758939 DOI: 10.1016/j.ejphar.2019.172819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/12/2019] [Accepted: 11/18/2019] [Indexed: 11/18/2022]
Abstract
The role of the renin-angiotensin-aldosterone system and arginine vasopressin (AVP) as humoral components in maintaining blood pressure (BP) during hemorrhagic shock (HS) is well established. However, little is known about the role of angiotensin II (Ang II) and AVP in the control of preganglionic sympathetic neuron activity. We studied the effects evoked by spinal Ang II type I (AT1) and V1a receptors antagonism on cardiovascular and sympathetic responses during HS. A catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anesthetized rats. The effects of HS on BP, heart rate (HR), and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were analyzed in the presence or absence (HS rats) of intrathecally injected losartan (HS-Los rats) or V1a antagonist (HS-V1a rats). The right femoral artery was catheterized for bleeding. Using a 5 ml syringe, hemorrhage was maintained continuously until a BP reduction of ~50 mmHg was achieved. We found that bleeding caused a reflex increase in HR, rSNA and sSNA in the HS rats. However, such responses were attenuated in the HS-Los rats. HS-V1a rats showed a reflex increase in HR, rSNA and sSNA in terms of frequency (spikes/s) but not in amplitude. Nevertheless, the BP recovery of the groups was similar. Our data showed that spinal AT1 receptors are essential for sympathoexcitation during the acute phase of HS. Moreover, spinal AVP seems to be a neuromodulator that controls the recruitment of spinal sympathetic vasomotor neurons during the acute phase of HS.
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Affiliation(s)
- Maycon I O Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Gustavo R Martins
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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14
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Nishi EE, Almeida VR, Amaral FG, Simon KA, Futuro-Neto HA, Pontes RB, Cespedes JG, Campos RR, Bergamaschi CT. Melatonin attenuates renal sympathetic overactivity and reactive oxygen species in the brain in neurogenic hypertension. Hypertens Res 2019; 42:1683-1691. [PMID: 31316170 DOI: 10.1038/s41440-019-0301-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/20/2019] [Accepted: 06/26/2019] [Indexed: 01/26/2023]
Abstract
Sympathetic overactivation contributes to the pathogenesis of both experimental and human hypertension. We have previously reported that oxidative stress in sympathetic premotor neurons leads to arterial baroreflex dysfunction and increased sympathetic drive to the kidneys in an experimental model of neurogenic hypertension. In this study, we hypothesized that melatonin, a potent antioxidant, may be protective in the brainstem regions involved in the tonic and reflex control of blood pressure (BP) in renovascular hypertensive rats. Neurogenic hypertension was induced by placing a silver clip (gap of 0.2 mm) around the left renal artery, and after 5 weeks of renal clip placement, the rats were treated orally with melatonin (30 mg/kg/day) by gavage for 15 days. At the end of melatonin treatment, we evaluated baseline mean arterial pressure (MAP), renal sympathetic nerve activity (rSNA), and the baroreflex control of heart rate (HR) and rSNA. Reactive oxygen species (ROS) were detected within the brainstem regions by dihydroethidium staining. Melatonin treatment effectively reduced baseline MAP and sympathoexcitation to the ischemic kidney in renovascular hypertensive rats. The baroreflex control of HR and rSNA were improved after melatonin treatment in the hypertensive group. Moreover, there was a preferential decrease in ROS within the rostral ventrolateral medulla (RVLM) and the nucleus of the solitary tract (NTS). Therefore, our study indicates that melatonin is effective in reducing renal sympathetic overactivity associated with decreased ROS in brainstem regions that regulate BP in an experimental model of neurogenic hypertension.
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Affiliation(s)
- Erika E Nishi
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Vitor R Almeida
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Fernanda G Amaral
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Karin A Simon
- Department of Biological Sciences, Campus Diadema, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Roberto B Pontes
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Juliana G Cespedes
- Institute of Science and Technology, Campus São José dos Campos, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology, Campus São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
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15
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Oliveira LF, Pinheiro DJLL, Rodrigues LD, Reyes-Garcia SZ, Nishi EE, Ormanji MS, Faber J, Cavalheiro EA. Behavioral, electrophysiological and neuropathological characteristics of the occurrence of hypertension in pregnant rats. Sci Rep 2019; 9:4051. [PMID: 30858526 PMCID: PMC6412065 DOI: 10.1038/s41598-019-40969-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 02/22/2019] [Indexed: 12/26/2022] Open
Abstract
Pre-eclampsia (PE) affects approximately 2 to 8% of pregnant women, causing blood pressure above 140 × 90 mmHg and proteinuria, normally after the 20th gestation week. If unsuccessfully treated, PE can lead to self-limited seizures (Eclampsia) that could eventually result in death of the mother and her fetus. The present study reports an experimental model of preeclampsia hypertension in pregnant (HP) and non-pregnant (H) Wistar rats by partially clamping one of their renal arteries. Pregnant (P) and non-pregnant (C) controls were provided. Differently from controls (C and P), H and HP animals presented a steady rise in BP two weeks after renal artery clamping. Injection of pentylenetetrazol (PTZ) induced behavioral and electroencephalographic seizures in all groups, which were increased in number, duration, amplitude and power accompanied by decreased latency in HP animals (p < 0.05). Consistent results were obtained in in vitro experimentation. Immunohistochemistry of hippocampus tissue in HP animals showed decreased density of neurons nuclei in CA1, CA3 and Hilus and increased density of astrocytes in CA1, CA3 and gyrus (p < 0.05). The present findings show that the clamping of one renal arteries to 0.15 mm and PTZ administration were able to induce signs similar to human PE in pregnant Wistar rats.
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Affiliation(s)
- Leandro F Oliveira
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil.
| | | | - Laís D Rodrigues
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | - Selvin Z Reyes-Garcia
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
- Department of morphological science, Faculty of Medical Sciences, National Autonomous University of Honduras, Tegucigalpa, Honduras
| | - Erika E Nishi
- Department of Physiology, UNIFESP/EPM, São Paulo, Brazil
| | | | - Jean Faber
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | - Esper A Cavalheiro
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
- Centro Nacional de Pesquisa em Energia e Materiais, (CNPEM) - 13083-970 Campinas, SP, Brazil
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16
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Poles WA, Nishi EE, de Oliveira MB, Eugênio AIP, de Andrade TA, Campos AHFM, de Campos RR, Vassallo J, Alves AC, Scapulatempo Neto C, Paes RAP, Landman G, Zerbini MCN, Colleoni GWB. Targeting the polarization of tumor-associated macrophages and modulating mir-155 expression might be a new approach to treat diffuse large B-cell lymphoma of the elderly. Cancer Immunol Immunother 2019; 68:269-282. [PMID: 30430204 PMCID: PMC11028330 DOI: 10.1007/s00262-018-2273-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 11/08/2018] [Indexed: 11/25/2022]
Abstract
Aging immune deterioration and Epstein-Barr (EBV) intrinsic mechanisms play an essential role in EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly (EBV + DLBCLe) pathogenesis, through the expression of viral proteins, interaction with host molecules and epigenetic regulation, such as miR-155, required for induction of M1 phenotype of macrophages. This study aims to evaluate the relationship between macrophage polarization pattern in the tumor microenvironment and relative expression of miR-155 in EBV + DLBCLe and EBV-negative DLBCL patients. We studied 28 EBV + DLBCLe and 65 EBV-negative DLBCL patients. Tumor-associated macrophages (TAM) were evaluated by expression of CD68, CD163 and CD163/CD68 ratio (degree of M2 polarization), using tissue microarray. RNA was extracted from paraffin-embedded tumor samples for miR-155 relative expression study. We found a significantly higher CD163/CD68 ratio in EBV + DLBCLe compared to EBV-negative DLBCL. In EBV-negative DLBCL, CD163/CD68 ratio was higher among advanced-staged/high-tumor burden disease and overexpression of miR-155 was associated with decreased polarization to the M2 phenotype of macrophages. The opposite was observed in EBV + DLBCLe patients: we found a positive association between miR-155 relative expression and CD163/CD68 ratio, which was not significant after outlier exclusion. We believe that the higher CD163/CD68 ratio in this group is probably due to the presence of the EBV since it directly affects macrophage polarization towards M2 phenotype through cytokine secretion in the tumor microenvironment. Therapeutic strategies modulating miR-155 expression or preventing immuno-regulatory and pro-tumor macrophage polarization could be adjuvants in EBV + DLBCLe therapy since this entity has a rich infiltration of M2 macrophages in its tumor microenvironment.
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MESH Headings
- Aged
- Aged, 80 and over
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, Myelomonocytic/immunology
- Antigens, Differentiation, Myelomonocytic/metabolism
- Epstein-Barr Virus Infections/complications
- Epstein-Barr Virus Infections/immunology
- Epstein-Barr Virus Infections/virology
- Female
- Gene Expression Regulation, Neoplastic/immunology
- Herpesvirus 4, Human/immunology
- Herpesvirus 4, Human/physiology
- Humans
- Lymphoma, Large B-Cell, Diffuse/complications
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/immunology
- Macrophage Activation/immunology
- Macrophages/classification
- Macrophages/immunology
- Macrophages/metabolism
- Male
- MicroRNAs/genetics
- MicroRNAs/immunology
- Middle Aged
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/metabolism
- Tumor Microenvironment/genetics
- Tumor Microenvironment/immunology
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Affiliation(s)
- Wagner A Poles
- Department of Clinical and Experimental Oncology, Universidade Federal de São Paulo, Rua Diogo de Faria, 824, 5° andar, Hemocentro, CEP 04037-002, Sao Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Mariana B de Oliveira
- Department of Clinical and Experimental Oncology, Universidade Federal de São Paulo, Rua Diogo de Faria, 824, 5° andar, Hemocentro, CEP 04037-002, Sao Paulo, Brazil
| | - Angela I P Eugênio
- Department of Clinical and Experimental Oncology, Universidade Federal de São Paulo, Rua Diogo de Faria, 824, 5° andar, Hemocentro, CEP 04037-002, Sao Paulo, Brazil
| | - Tathiana A de Andrade
- Department of Clinical and Experimental Oncology, Universidade Federal de São Paulo, Rua Diogo de Faria, 824, 5° andar, Hemocentro, CEP 04037-002, Sao Paulo, Brazil
| | | | - Ruy R de Campos
- Department of Physiology, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - José Vassallo
- Department of Pathology, AC Camargo Cancer Center, Sao Paulo, Brazil
| | - Antonio C Alves
- Department of Pathology, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | | | | | - Gilles Landman
- Department of Pathology, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | | | - Gisele W B Colleoni
- Department of Clinical and Experimental Oncology, Universidade Federal de São Paulo, Rua Diogo de Faria, 824, 5° andar, Hemocentro, CEP 04037-002, Sao Paulo, Brazil.
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17
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Nishi EE, Lopes NR, Gomes GN, Perry JC, Sato AYS, Naffah-Mazzacoratti MG, Bergamaschi CT, Campos RR. Renal denervation reduces sympathetic overactivation, brain oxidative stress, and renal injury in rats with renovascular hypertension independent of its effects on reducing blood pressure. Hypertens Res 2018; 42:628-640. [PMID: 30573809 DOI: 10.1038/s41440-018-0171-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 10/19/2018] [Accepted: 10/31/2018] [Indexed: 12/27/2022]
Abstract
The underlying mechanisms by which renal denervation (RD) decreases blood pressure (BP) remain incompletely understood. In this study, we investigated the effects of ischemic kidney denervation on different sympathetic outflows, brain and renal expression of angiotensin-II receptors, oxidative stress and renal function markers in the 2-kidney, 1-clip (2K-1C) rat model. Surgical RD was performed in Wistar male rats 4-5 weeks after clip implantation. After 10 days of RD, BP, and the activity of sympathetic nerves projecting to the contralateral kidney (rSNA) and splanchnic region were partially reduced in 2K-1C rats, with no change in systemic renin-angiotensin system (RAS). To distinguish the effects of RD from the reduction in BP, 2K-1C rats were treated with hydralazine by oral gavage (25 mg/kg/day for 1 week). RD, but not hydralazine, normalized oxidative stress in the sympathetic premotor brain regions and improved intrarenal RAS, renal injury, and proteinuria. Furthermore, different mechanisms led to renal injury and oxidative stress in the ischemic and contralateral kidneys of 2K-1C rats. Injury and oxidative stress in the ischemic kidney were driven by the renal nerves. Although RD attenuated rSNA, injury and oxidative stress persisted in the contralateral kidney, probably due to increased BP. Therefore, nerves from the ischemic kidney at least partially contribute to the increase in BP, sympathetic outflows, brain oxidative stress, and renal alterations in rats with renovascular hypertension. Based on these findings, the reduction in oxidative stress in the brain is a central mechanism that contributes to the effects of RD on Goldblatt hypertension.
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Affiliation(s)
- Erika E Nishi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
| | - Nathalia R Lopes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Guiomar N Gomes
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Juliana C Perry
- Department of Psychobiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Alex Y S Sato
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Maria G Naffah-Mazzacoratti
- Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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18
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Lincevicius GS, Shimoura CG, Nishi EE, Oliveira T, Cespedes JG, Bergamaschi CT, Campos RR. Differential effects of renal denervation on arterial baroreceptor function in Goldblatt hypertension model. Auton Neurosci 2017; 208:43-50. [PMID: 28688830 DOI: 10.1016/j.autneu.2017.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 06/09/2017] [Accepted: 06/19/2017] [Indexed: 01/19/2023]
Abstract
Sympathetic vasomotor activity is significantly increased in renovascular hypertension. Renal denervation (DnX) has emerged as a novel therapy for resistant hypertension to drug therapy. However, the underlying mechanisms regarding the reduction in blood pressure (BP) after DnX remain unclear. Thus, the aim of this study was to evaluate the effects of DnX of a clipped kidney on the baseline and baroreceptor reflex control of post-ganglionic sympathetic activity to the contralateral kidney (rSNA) and lumbar (lSNA) nerves in Goldblatt hypertensive rats (2K1C). Renal denervation of an ischaemic kidney (DxX - all visible bundles of nerves were dissected - 10% phenol) was performed 5weeks after clipping (gap width: 0.2mm). Ten days after DnX, BP was significantly reduced (16%) in the 2K1C compared with the undenervated 2K1C (p<0.05). DnX significantly reduced basal rSNA (control group (CT): 110±8, n=14; 2K1C: 150±8, n=12; 2K1C DnX: 89±7, spikes per second (spikes/s); p<0.05, n=8) and lSNA (CT: 137±8, n=8; 2K1C: 202±7, n=11; 2K1C DnX: 131±7, spikes/s; p<0.05, n=8) only in 2K1C rats. DnX significantly improved the arterial baroreceptor sensitivity of rSNA (CT: -2.3±0.2, n=11; 2K1C: -0.7±0.1, n=8; 2K1C DnX: -1.5±0.2, spikes/s/mmHg; p<0.05, n=5) and heart rate for tachycardic response (CT: -3.9±0.5, n=7; 2K1C: -1.9±0.1, n=8; 2K1C DnX: -3.3±0.4, bpm/mmHg; p<0.05, n=8), but not for lSNA in 2K1C rats. The results show that DnX normalized baseline sympathetic vasomotor activity to the lumbar and renal nerves, followed by a differential improvement in the arterial baroreceptor sensitivity. Whether the baroreceptor function sensitivity improvement induced by DnX is a cause or a consequence of BP reduction remains to be determined.
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Affiliation(s)
- Gisele S Lincevicius
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Caroline G Shimoura
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Tales Oliveira
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Juliana G Cespedes
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, Campus São José dos Campos, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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19
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Nishi EE, Martins BS, Milanez MI, Lopes NR, de Melo JF, Pontes RB, Girardi AC, Campos RR, Bergamaschi CT. Stimulation of renal afferent fibers leads to activation of catecholaminergic and non-catecholaminergic neurons in the medulla oblongata. Auton Neurosci 2017; 204:48-56. [DOI: 10.1016/j.autneu.2017.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 12/17/2022]
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20
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Shimoura CG, Lincevicius GS, Nishi EE, Girardi ACC, Simon KA, Bergamaschi CT, Campos RR. Increased Dietary Salt Changes Baroreceptor Sensitivity and Intrarenal Renin-Angiotensin System in Goldblatt Hypertension. Am J Hypertens 2017; 30:28-36. [PMID: 27629265 DOI: 10.1093/ajh/hpw107] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 08/18/2016] [Accepted: 08/19/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Renovascular hypertension (2-kidney 1-clip model (2K1C)) is characterized by renin-angiotensin system (RAS) activation. Increased Angiotensin II (AngII) leads to sympathoexcitation, oxidative stress, and alterations in sodium and water balance. AIM The aim of this study was to evaluate whether a discrete increase in sodium chloride intake in 2K1C rats leads to changes in cardiovascular and autonomic function, oxidative stress, and renin angiotensin aldosterone system. METHODS After 4 weeks of induction of hypertension, rats were fed a normal sodium diet (0.4% NaCl) or a high-sodium diet (2% NaCl) for 2 consecutive weeks. Experiments were carried out for 6 weeks after clipping. Mean arterial pressure (MAP), renal sympathetic nerve activity (rSNA), arterial baroreflex control of rSNA, and heart rate (HR) were assessed. Thiobarbituric acid reactive substances and glutathione were measured as indicators of systemic oxidative stress. Angiostensin-converting enzyme (ACE), ACE2, and angiotensinogen were evaluated in clipped and unclipped kidneys as also urinary angiotensinogen and plasma renin activity. Angiotensinogen, plasma renin activity (PRA) and angiotensin-converting enzyme (ACE) and ACE2 in clipped and unclipped kidneys were evaluated. RESULTS High-sodium diet did not change systemic oxidative stress, and basal values of MAP, HR, or rSNA; however, increased renal (-0.7±0.2 vs. -1.5±0.1 spikes/s/mm Hg) and cardiac (-0.9±0.14 vs. -1.5±0.14 bpm/mm Hg) baroreceptor reflex sensitivity in 2K1C rats. Although there was no alteration in PRA, a high-salt diet significantly decreased urinary angiotensinogen, ACE, and ACE2 expressions in the clipped and unclipped kidneys. CONCLUSIONS Increased arterial baroreceptor control associated with a suppression of the intrarenal RAS in the 2K1C rats on high-salt diet provide a salt-resistant effect on hypertension and sympathoexcitation in renovascular hypertensive rats.
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Affiliation(s)
- Caroline G Shimoura
- Cardiovascular Division-Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Gisele S Lincevicius
- Cardiovascular Division-Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division-Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Adriana C C Girardi
- Heart Institute (InCor) University of São Paulo Medical School, São Paulo, São Paulo, Brazil
| | - Karin A Simon
- Department of Biological Sciences, Universidade Federal de São Paulo, Diadema, Brazil
| | - Cassia T Bergamaschi
- Cardiovascular Division-Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division-Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil;
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Argeri R, Nishi EE, Volpini RA, Palma BD, Tufik S, Gomes GN. Sleep restriction during pregnancy and its effects on blood pressure and renal function among female offspring. Physiol Rep 2016; 4:4/16/e12888. [PMID: 27796270 PMCID: PMC5002907 DOI: 10.14814/phy2.12888] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/11/2016] [Indexed: 12/15/2022] Open
Abstract
The influence of sleep restriction (SR) during pregnancy on blood pressure and renal function among female adult offspring was investigated. Pregnant Wistar rats were distributed into control and SR groups. The SR was performed between the 14th and 20th days of pregnancy (multiple platforms method for 20 h/day). At 2 months of age, half of the offspring from both groups were subjected to an ovariectomy (ovx), and the other half underwent sham surgery. The groups were as follows: control sham (Csham), control ovx (Covx), SR sham (SRsham), and SR ovx (SRovx). Renal function markers and systolic blood pressure (BPi, indirect method) were evaluated at 4, 6, and 8 months. Subsequently, the rats were euthanized, kidneys were removed, and processed for morphological analyses of glomerular area (GA), number of glomeruli per mm3 (NG), and kidney mass (KM). Increased BPi was observed in the Covx, SRsham, and SRovx groups compared to Csham at all ages. Increased plasma creatinine concentration and decreased creatinine clearance were observed in the SRsham and SRovx groups compared to the Csham and Covx groups. The SRovx group showed higher BPi and reduced creatinine clearance compared to all other groups. The SRovx group showed reduced values of GA and KM, as well as increased NG, macrophage infiltration, collagen deposit, and ACE1 expression at the renal cortex. Therefore, SR during pregnancy might be an additional risk factor for developing renal dysfunction and increasing BP in female adult offspring. The absence of female hormones exacerbates the changes caused by SR.
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Affiliation(s)
- Rogério Argeri
- Department of Physiology, Escola Paulista de Medicina - UNIFESP, São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology, Escola Paulista de Medicina - UNIFESP, São Paulo, Brazil
| | - Rildo A Volpini
- Department of Psychobiology, Escola Paulista de Medicina - UNIFESP, São Paulo, Brazil
| | - Beatriz D Palma
- Basic Research Laboratory - LIM12, Nephrology - Faculty of Medicine, USP, São Paulo, São Paulo, Brazil.,Centro Universitário São Camilo, São Paulo, Brazil
| | - Sergio Tufik
- Basic Research Laboratory - LIM12, Nephrology - Faculty of Medicine, USP, São Paulo, São Paulo, Brazil
| | - Guiomar N Gomes
- Department of Physiology, Escola Paulista de Medicina - UNIFESP, São Paulo, Brazil
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Pontes RB, Girardi ACC, Nishi EE, Campos RR, Bergamaschi CT. Crosstalk between the renal sympathetic nerve and intrarenal angiotensin II modulates proximal tubular sodium reabsorption. Exp Physiol 2016; 100:502-6. [PMID: 25858030 DOI: 10.1113/ep085075] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/07/2015] [Indexed: 01/12/2023]
Abstract
NEW FINDINGS What is the topic of this review? The sympathetic control of renal sodium tubular reabsorption is dependent on activation of the intrarenal renin-angiotensin system and activation of the angiotensin II type 1 (AT1 ) receptor by angiotensin II. What advances does it highlight? Despite the fact that the interaction between the sympathetic nervous system and angiotensin II regarding salt reabsorption is a well-known classical mechanism for the maintenance of extracellular volume homeostasis, the underlying molecular signalling is not clearly understood. It has been shown recently that renal nerve stimulation increases intrarenal angiotensin II and activates the AT1 receptor, triggering a signalling cascade that leads to elevations of Na(+) -H(+) exchanger isoform 3-mediated tubular transport. In this short review, the crosstalk between intrarenal angiotensin II and renal nerve activity and its effect on sodium reabsorption is addressed. In this review, we address the importance of the interaction between the sympathetic nervous system and intrarenal renin-angiotensin system in modulating renal tubular handling of sodium and water. We have recently shown that increased Na(+) -H(+) exchanger isoform 3 (NHE3) activity induced by renal nerve stimulation (RNS) depends on the activation of the angiotensin II type 1 (AT1 ) receptor by angiotensin II (Ang II). Low-frequency RNS resulted in higher levels of intrarenal angiotensinogen and Ang II independent of changes in blood pressure, the glomerular filtration rate and systemic angiotensinogen. Angiotensin II, via the AT1 receptor, triggered an intracellular pathway activating NHE3 in the renal cortex, leading to antinatriuresis and antidiuresis. Pharmacological blockade of the AT1 receptor with losartan prior to RNS abolished both the functional and the molecular responses, suggesting that intrarenal Ang II acting via the AT1 receptor is a major factor for NHE3-mediated sodium and water reabsorption induced by RNS.
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Affiliation(s)
- Roberto B Pontes
- Department of Physiology, Division of Cardiovascular Physiology, Federal University of Sao Paulo, São Paulo, SP, Brazil
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Veiga G, Estrela H, Nishi EE, Gomes G, Sato A, Campos R, Bergamaschi C. Effects of nebivolol on sympatoexcitation and renal fibrosis in a model of chronic kidney disease. Auton Neurosci 2015. [DOI: 10.1016/j.autneu.2015.07.198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Lincevicius GS, Shimoura CG, Nishi EE, Perry JC, Casarini DE, Gomes GN, Bergamaschi CT, Campos RR. Aldosterone Contributes to Sympathoexcitation in Renovascular Hypertension. Am J Hypertens 2015; 28:1083-90. [PMID: 25628418 DOI: 10.1093/ajh/hpu300] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 12/18/2014] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Although angiotensin II (Ang II) is essential to the development of renovascular hypertension, aldosterone plays a role as well. Recent studies have demonstrated a cross-talk between Ang II type 1 and mineralocorticoid receptors in the brain and kidneys. However, the role of aldosterone in the autonomic and renal dysfunction of renovascular hypertension is not well understood. AIM The current study evaluated whether aldosterone contributes to cardiovascular and renal dysfunction in the 2 kidney-1 clip (2K1C) model. METHODS Mean arterial pressure (MAP) and baroreceptor reflex for control of the heart rate were evaluated in 2K1C treated or not treated with spironolactone (200mg/kg/day, 7 days). Tonic and reflex control of renal sympathetic nerve activity (rSNA) were assessed in urethane-anaesthetized rats. Plasma renin activity (PRA), kidney renin protein expression, renal injury, and central AT1 receptor protein expression were assessed. RESULTS Spiro reduced MAP (198±4 vs. 170±9mm Hg; P < 0.05), normalized rSNA (147±9 vs. 96±10 pps; P < 0.05), and increased renal baroreceptor reflex sensitivity in the 2K1C rats. Spiro reduced α-smooth muscle actin expression in the nonclipped kidney in the 2K1C group (5±0.6 vs. 1.1±0.2%; P < 0.05). There was no change in PRA; however, a decrease in renin protein expression in the nonclipped kidney was found in the 2K1C treated group (217±30 vs. 160±19%; P < 0.05). Spiro treatment decreased AT1 receptor in the central nervous system (CNS) only in 2K1C rats (138±10 vs. 84±12%; P < 0.05). CONCLUSION Aldosterone contributes to autonomic dysfunction and intrarenal injury in 2K1C, these effects are mediated by the CNS.
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Affiliation(s)
- Gisele S Lincevicius
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Caroline G Shimoura
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Erika E Nishi
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Juliana C Perry
- Department of Psychobiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Dulce E Casarini
- Nephrology Division, Department of Medicine - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Guiomar N Gomes
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cássia T Bergamaschi
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ruy R Campos
- Department of Physiology - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil;
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Campos RR, Oliveira-Sales EB, Nishi EE, Paton JFR, Bergamaschi CT. Mechanisms of renal sympathetic activation in renovascular hypertension. Exp Physiol 2015; 100:496-501. [DOI: 10.1113/expphysiol.2014.079855] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/26/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Ruy R. Campos
- Department of Physiology, Cardiovascular Division; Universidade Federal de São Paulo; São Paulo Brazil
| | | | - Erika E. Nishi
- Department of Physiology, Cardiovascular Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - Julian F. R. Paton
- School of Physiology & Pharmacology, Bristol CardioVascular; University of Bristol; Medical Sciences Building Bristol BS8 1TD UK
| | - Cassia T. Bergamaschi
- Department of Physiology, Cardiovascular Division; Universidade Federal de São Paulo; São Paulo Brazil
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Booth LC, Schlaich MP, Nishi EE, Yao ST, Xu J, Ramchandra R, Lambert GW, May CN. Short-term effects of catheter-based renal denervation on cardiac sympathetic drive and cardiac baroreflex function in heart failure. Int J Cardiol 2015; 190:220-6. [PMID: 25920032 DOI: 10.1016/j.ijcard.2015.03.440] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/08/2015] [Accepted: 03/16/2015] [Indexed: 01/18/2023]
Abstract
OBJECTIVES Sympathetic drive, especially to the heart, is elevated in heart failure and is strongly associated with poor outcome. The mechanisms causing the increased sympathetic drive to the heart remain poorly understood. Catheter-based renal denervation (RDN), which reduces blood pressure (BP) and sympathetic drive in hypertensive patients, is a potential treatment in heart failure. The aim of this study was to investigate the short-term effects of catheter-based RDN on BP, heart rate (HR) and cardiac sympathetic nerve activity (CSNA) and on baroreflex function in a conscious, large animal model of heart failure. METHODS Adult Merino ewes were paced into heart failure (ejection fraction<40%) and then instrumented to directly record CSNA. The resting levels and baroreflex control of CSNA and HR were measured before and 24h after bilateral renal (n=6) or sham (n=6) denervation. RDN was performed using the Symplicity Flex Catheter System® (Medtronic) using the same algorithm as in patients. RESULTS Catheter-based RDN significantly reduced resting diastolic BP (P<0.01) and mean arterial blood pressure (P<0.05), but did not change resting HR or CSNA compared with sham denervation. Renal denervation reduced the BP at which CSNA was at 50% of maximum (BP50; P<0.005) compared with sham denervation. CONCLUSIONS In an ovine model of heart failure, catheter-based RDN did not reduce resting CSNA in the short-term. There was, however, a lack of a reflex increase in CSNA in response to the fall in arterial pressure due to a leftward shift in the baroreflex control of CSNA, which may be due to denervation of renal efferent and/or afferent nerves.
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Affiliation(s)
- Lindsea C Booth
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia.
| | | | - Erika E Nishi
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil
| | - Song T Yao
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
| | - Jianzhong Xu
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; Shanghai Institute of Hypertension, Ruijin Hospital, Shanghai, China
| | - Rohit Ramchandra
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Gavin W Lambert
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
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Pontes RB, Crajoinas RO, Nishi EE, Oliveira-Sales EB, Girardi AC, Campos RR, Bergamaschi CT. Renal nerve stimulation leads to the activation of the Na+/H+ exchanger isoform 3 via angiotensin II type I receptor. Am J Physiol Renal Physiol 2015; 308:F848-56. [PMID: 25656367 DOI: 10.1152/ajprenal.00515.2014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/29/2015] [Indexed: 01/13/2023] Open
Abstract
Renal nerve stimulation at a low frequency (below 2 Hz) causes water and sodium reabsorption via α1-adrenoreceptor tubular activation, a process independent of changes in systemic blood pressure, renal blood flow, or glomerular filtration rate. However, the underlying mechanism of the reabsorption of sodium is not fully understood. Since the sympathetic nervous system and intrarenal ANG II appear to act synergistically to mediate the process of sodium reabsorption, we hypothesized that low-frequency acute electrical stimulation of the renal nerve (ESRN) activates NHE3-mediated sodium reabsorption via ANG II AT1 receptor activation in Wistar rats. We found that ESRN significantly increased urinary angiotensinogen excretion and renal cortical ANG II content, but not the circulating angiotensinogen levels, and also decreased urinary flow and pH and sodium excretion via mechanisms independent of alterations in creatinine clearance. Urinary cAMP excretion was reduced, as was renal cortical PKA activity. ESRN significantly increased NHE3 activity and abundance in the apical microvillar domain of the proximal tubule, decreased the ratio of phosphorylated NHE3 at serine 552/total NHE3, but did not alter total cortical NHE3 abundance. All responses mediated by ESRN were completely abolished by a losartan-mediated AT1 receptor blockade. Taken together, our results demonstrate that higher NHE3-mediated proximal tubular sodium reabsorption induced by ESRN occurs via intrarenal renin angiotensin system activation and triggering of the AT1 receptor/inhibitory G-protein signaling pathway, which leads to inhibition of cAMP formation and reduction of PKA activity.
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Affiliation(s)
- Roberto B Pontes
- Departamento de Fisiologia, Disciplina de Fisiologia Cardiovascular, Universidade Federal de São Paulo, São Paulo, Brazil; and
| | - Renato O Crajoinas
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Erika E Nishi
- Departamento de Fisiologia, Disciplina de Fisiologia Cardiovascular, Universidade Federal de São Paulo, São Paulo, Brazil; and
| | - Elizabeth B Oliveira-Sales
- Departamento de Fisiologia, Disciplina de Fisiologia Cardiovascular, Universidade Federal de São Paulo, São Paulo, Brazil; and
| | - Adriana C Girardi
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Ruy R Campos
- Departamento de Fisiologia, Disciplina de Fisiologia Cardiovascular, Universidade Federal de São Paulo, São Paulo, Brazil; and
| | - Cássia T Bergamaschi
- Departamento de Fisiologia, Disciplina de Fisiologia Cardiovascular, Universidade Federal de São Paulo, São Paulo, Brazil; and
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Booth LC, Nishi EE, Yao ST, Ramchandra R, Lambert GW, Schlaich MP, May CN. Reinnervation following catheter-based radio-frequency renal denervation. Exp Physiol 2015; 100:485-90. [PMID: 25573386 DOI: 10.1113/expphysiol.2014.079871] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/23/2014] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? Does catheter-based renal denervation effectively denervate the afferent and efferent renal nerves and does reinnervation occur? What advances does it highlight? Following catheter-based renal denervation, the afferent and efferent responses to electrical stimulation were abolished, renal sympathetic nerve activity was absent, and levels of renal noradrenaline and immunohistochemistry for tyrosine hydroxylase and calcitonin gene-related peptide were significantly reduced. By 11 months after renal denervation, both the functional responses and anatomical markers of afferent and efferent renal nerves had returned to normal, indicating reinnervation. Renal denervation reduces blood pressure in animals with experimental hypertension and, recently, catheter-based renal denervation was shown to cause a prolonged decrease in blood pressure in patients with resistant hypertension. The randomized, sham-controlled Symplicity HTN-3 trial failed to meet its primary efficacy end-point, but there is evidence that renal denervation was incomplete in many patients. Currently, there is little information regarding the effectiveness of catheter-based renal denervation and the extent of reinnervation. We assessed the effectiveness of renal nerve denervation with the Symplicity Flex catheter and the functional and anatomical reinnervation at 5.5 and 11 months postdenervation. In anaesthetized, non-denervated sheep, there was a high level of renal sympathetic nerve activity, and electrical stimulation of the renal nerve increased blood pressure and reduced heart rate (afferent response) and caused renal vasoconstriction and reduced renal blood flow (efferent response). Immediately after renal denervation, renal sympathetic nerve activity and the responses to electrical stimulation were absent, indicating effective denervation. By 11 months after denervation, renal sympathetic nerve activity was present and the responses to electrical stimulation were normal, indicating reinnervation. Anatomical measures of renal innervation by sympathetic efferent nerves (tissue noradrenaline and tyrosine hydroxylase) and afferent sensory nerves (calcitonin gene-related peptide) demonstrated large decreases at 1 week postdenervation, but normal levels at 11 months postdenervation. In summary, catheter-based renal denervation is effective, but reinnervation occurs. Studies of central and renal changes postdenervation are required to understand the causes of the prolonged hypotensive response to catheter-based renal denervation in human hypertension.
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Affiliation(s)
- Lindsea C Booth
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
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Nishi EE, Bergamaschi CT, Campos RR. The crosstalk between the kidney and the central nervous system: the role of renal nerves in blood pressure regulation. Exp Physiol 2015; 100:479-84. [PMID: 25599970 DOI: 10.1113/expphysiol.2014.079889] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 12/09/2014] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic dysfunction is the predominant contributor to systemic hypertension is still debated. In this review, we focus on the role of the renal nerves in a model of renovascular hypertension. The sympathetic nervous system influences the renal regulation of arterial pressure and body fluid composition. Anatomical and physiological evidence has shown that sympathetic nerves mediate changes in urinary sodium and water excretion by regulating the renal tubular water and sodium reabsorption throughout the nephron, changes in the renal blood flow and the glomerular filtration rate by regulating the constriction of renal vasculature, and changes in the activity of the renin-angiotensin system by regulating the renin release from juxtaglomerular cells. Additionally, renal sensory afferent fibres project to the autonomic central nuclei that regulate blood pressure. Hence, renal nerves play a key role in the crosstalk between the kidneys and the CNS to maintain homeostasis in the body. Therefore, the increased sympathetic nerve activity to the kidney and the renal afferent nerve activity to the CNS may contribute to the outcome of diseases, such as hypertension.
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Affiliation(s)
- Erika E Nishi
- Department of Physiology, Cardiovascular Division, Universidade Federal de São Paulo, São Paulo, Brazil
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Booth LC, Nishi EE, Yao ST, Ramchandra R, Lambert GW, Schlaich MP, May CN. Reinnervation of renal afferent and efferent nerves at 5.5 and 11 months after catheter-based radiofrequency renal denervation in sheep. Hypertension 2014; 65:393-400. [PMID: 25403610 DOI: 10.1161/hypertensionaha.114.04176] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Previous studies indicate that catheter-based renal denervation reduces blood pressure and renal norepinephrine spillover in human resistant hypertension. The effects of this procedure on afferent sensory and efferent sympathetic renal nerves, and the subsequent degree of reinnervation, have not been investigated. We therefore examined the level of functional and anatomic reinnervation at 5.5 and 11 months after renal denervation using the Symplicity Flex catheter. In normotensive anesthetized sheep (n=6), electric stimulation of intact renal nerves increased arterial pressure from 99±3 to 107±3 mm Hg (afferent response) and reduced renal blood flow from 198±16 to 85±20 mL/min (efferent response). In a further group (n=6), immediately after denervation, renal sympathetic nerve activity was absent and the responses to electric stimulation were abolished. At 11 months after denervation (n=5), renal sympathetic nerve activity and the responses to electric stimulation were at normal levels. Immunohistochemical staining for renal efferent (tyrosine hydroxylase) and renal afferent nerves (calcitonin gene-related peptide), as well as renal norepinephrine levels, was normal 11 months after denervation. Findings at 5.5 months after denervation were similar (n=5). In summary, catheter-based renal denervation effectively ablated the renal afferent and efferent nerves in normotensive sheep. By 11 months after denervation the functional afferent and efferent responses to electric stimulation were normal. Reinnervation at 11 months after denervation was supported by normal anatomic distribution of afferent and efferent renal nerves. In view of this evidence, the mechanisms underlying the prolonged hypotensive effect of catheter-based renal denervation in human resistant hypertension need to be reassessed.
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Affiliation(s)
- Lindsea C Booth
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.).
| | - Erika E Nishi
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
| | - Song T Yao
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
| | - Rohit Ramchandra
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
| | - Gavin W Lambert
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
| | - Markus P Schlaich
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
| | - Clive N May
- From the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia (L.C.B., S.T.Y., R.R., C.N.M.); Baker IDI Heart and Diabetes Institute, Central Clinical School Monash University, Melbourne, Victoria, Australia (M.P.S., G.W.L.); and Department of Physiology, Cardiovascular Division, Federal University of São Paulo, São Paulo, Brazil (E.E.N.)
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Nishi EE, Bergamaschi CT, Oliveira-Sales EB, Simon KA, Campos RR. Losartan reduces oxidative stress within the rostral ventrolateral medulla of rats with renovascular hypertension. Am J Hypertens 2013; 26:858-65. [PMID: 23485486 DOI: 10.1093/ajh/hpt037] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Previous studies showed that the microinjection of antioxidants or the overexpression of superoxide dismutase within the rostral ventrolateral medulla (RVLM) reduces hypertension and sympathoexcitation in the 2-kidney, 1-clip (2K-1C) model. In this study, we hypothesized that angiotensin II (ANG II) type 1 receptor (AT1R) is involved in the oxidative stress within the RVLM and contributes to cardiovascular dysfunction in renovascular hypertension. METHODS Losartan (30mg/kg/day, oral gavage) was administered for 7 consecutive days by week 5 after implantation of the clip (gap width = 0.2mm). Mean arterial pressure, baroreflex, and renal sympathetic nerve activity (rSNA) were evaluated. Superoxide production was evaluated by dihydroethidium (DHE) staining within the RVLM and within a control area. Systemic oxidative stress was characterized by measurement of thiobarbituric acid reactive substances (TBARS) and total glutathione (tGSH) in the blood. RESULTS AT1R blockade significantly (P < 0.05) reduced hypertension by approximately 20% (n = 11) and sympathoexcitation to the kidneys by approximately 41% (n = 6) in the 2K-1C rats. Losartan treatment increased the baroreflex sensitivity of rSNA to pressor (67%) and depressor (140%) stimuli in the 2K-1C rats. AT1R blockade caused a significant (66%) reduction in DHE staining within the RVLM but not within the control area, reduced plasma TBARS (from 1.6±0.1 to 1.0±0.1 nmol/ml), and increased tGSH (from 3.4±0.4 to 5.2±0.3 μmol/g Hb) in the 2K-1C group only. CONCLUSIONS Our findings suggest that the beneficial effects of ANG II blockade in renovascular hypertension are partly due to preferential reduction of oxidative stress in the RVLM.
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Affiliation(s)
- Erika E Nishi
- Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil
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Garcia ML, Nishi EE, Lincevicius GS, Veiga GRL, Pontes RB, Campos RR, Oyama L, Bergamaschi CT. Effects of Chronic Green Tea (GT) or Green Tea Extract (GTE) treatment in cardiovascular function in Hypertensive Rats. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1192.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Erika E Nishi
- PhysiologyUniversidade Federal de São PauloSão PauloBrazil
| | | | | | | | - Ruy R Campos
- PhysiologyUniversidade Federal de São PauloSão PauloBrazil
| | - Lila Oyama
- PhysiologyUniversidade Federal de São PauloSão PauloBrazil
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Campos RR, Oliveira-Sales EB, Nishi EE, Boim MA, Dolnikoff MS, Bergamaschi CT. The role of oxidative stress in renovascular hypertension. Clin Exp Pharmacol Physiol 2011; 38:144-52. [PMID: 20678153 DOI: 10.1111/j.1440-1681.2010.05437.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. There is mounting evidence that increased oxidative stress and sympathetic nerve activity play important roles in renovascular hypertension. In the present review, we focus on the importance of oxidative stress in two distinct populations of neurons involved with cardiovascular regulation: those of the rostral ventrolateral medulla (RVLM) and those of the paraventricular nucleus of the hypothalamus (PVN) in the maintenance of sympathoexcitation and hypertension in two kidney-one clip (2K1C) hypertensive rats. Furthermore, the role of oxidative stress in the clipped kidney is also discussed. 2. In the studies reviewed in this article, it was found that hypertension and renal sympathoexcitation in 2K1C rats were associated with an increase in Angiotensin II type one receptor (AT(1) ) expression and in oxidative markers within the RVLM, PVN and in the clipped kidneys of 2K1C rats. Furthermore, acute or chronic anti-oxidant treatment decreased blood pressure and sympathetic activity, and improved the baroreflex control of heart rate and renal sympathetic nerve activity in 2K1C rats. Tempol or vitamin C administration in the RVLM, PVN or systemically all reduced blood pressure and renal sympathetic activity. Cardiovascular improvement in response to chronic anti-oxidant treatment was associated with a downregulation of AT(1) receptors, as well as oxidative markers in the central nuclei and clipped kidney. 3. The data discussed in the present review support the idea that an increase in oxidative stress within the RVLM, PVN and in the ischaemic kidney plays a major role in the maintenance of sympathoexcitation and hypertension in 2K1C rats.
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Affiliation(s)
- Ruy R Campos
- Department of Physiology, Cardiovascular Division Department of Medicine, Nephrology Division, Federal University of São Paulo, São Paulo, Brazil.
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