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Rodionova K, Veelken R, Hilgers KF, Paulus EM, Linz P, Fischer MJM, Schenker M, Reeh P, Tiegs G, Ott C, Schmieder R, Schiffer M, Amann K, Ditting T. Afferent renal innervation in anti-Thy1.1 nephritis in rats. Am J Physiol Renal Physiol 2020; 319:F822-F832. [PMID: 33017188 DOI: 10.1152/ajprenal.00063.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Afferent renal nerves exhibit a dual function controlling central sympathetic outflow via afferent electrical activity and influencing intrarenal immunological processes by releasing peptides such as calcitonin gene-related peptide (CGRP). We tested the hypothesis that increased afferent and efferent renal nerve activity occur with augmented release of CGRP in anti-Thy1.1 nephritis, in which enhanced CGRP release exacerbates inflammation. Nephritis was induced in Sprague-Dawley rats by intravenous injection of OX-7 antibody (1.75 mg/kg), and animals were investigated neurophysiologically, electrophysiologically, and pathomorphologically 6 days later. Nephritic rats exhibited proteinuria (169.3 ± 10.2 mg/24 h) with increased efferent renal nerve activity (14.7 ± 0.9 bursts/s vs. control 11.5 ± 0.9 bursts/s, n = 11, P < 0.05). However, afferent renal nerve activity (in spikes/s) decreased in nephritis (8.0 ± 1.8 Hz vs. control 27.4 ± 4.1 Hz, n = 11, P < 0.05). In patch-clamp recordings, neurons with renal afferents from nephritic rats showed a lower frequency of high activity following electrical stimulation (43.4% vs. 66.4% in controls, P < 0.05). In vitro assays showed that renal tissue from nephritic rats exhibited increased CGRP release via spontaneous (14 ± 3 pg/mL vs. 6.8 ± 2.8 pg/ml in controls, n = 7, P < 0.05) and stimulated mechanisms. In nephritic animals, marked infiltration of macrophages in the interstitium (26 ± 4 cells/mm2) and glomeruli (3.7 ± 0.6 cells/glomerular cross-section) occurred. Pretreatment with the CGRP receptor antagonist CGRP8-37 reduced proteinuria, infiltration, and proliferation. In nephritic rats, it can be speculated that afferent renal nerves lose their ability to properly control efferent sympathetic nerve activity while influencing renal inflammation through increased CGRP release.
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Affiliation(s)
- Kristina Rodionova
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Roland Veelken
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
| | - Karl F Hilgers
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Eva-Maria Paulus
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Peter Linz
- Department of Radiology, University of Erlangen, Erlangen, Germany
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martina Schenker
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Physiology and Pathophysiology, University Erlangen, Erlangen, Germany
| | - Peter Reeh
- Department of Physiology and Pathophysiology, University Erlangen, Erlangen, Germany
| | - Gisa Tiegs
- Center of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Ott
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
| | - Roland Schmieder
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Mario Schiffer
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany
| | - Kerstin Amann
- Department of Nephropathology, University of Erlangen, Erlangen, Germany
| | - Tilmann Ditting
- Department of Internal Medicine 4 (Nephrology und Hypertension), University of Erlangen, Erlangen, Germany.,Department of Internal Medicine 4 (Nephrology und Hypertension), Paracelsus Private Medical School, Klinikum Nuremberg, Nuremberg, Germany
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Subramanian M, Mueller PJ. Altered Differential Control of Sympathetic Outflow Following Sedentary Conditions: Role of Subregional Neuroplasticity in the RVLM. Front Physiol 2016; 7:290. [PMID: 27486405 PMCID: PMC4949265 DOI: 10.3389/fphys.2016.00290] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/27/2016] [Indexed: 01/25/2023] Open
Abstract
Despite the classically held belief of an “all-or-none” activation of the sympathetic nervous system, differential responses in sympathetic nerve activity (SNA) can occur acutely at varying magnitudes and in opposing directions. Sympathetic nerves also appear to contribute differentially to various disease states including hypertension and heart failure. Previously we have reported that sedentary conditions enhanced responses of splanchnic SNA (SSNA) but not lumbar SNA (LSNA) to activation of the rostral ventrolateral medulla (RVLM) in rats. Bulbospinal RVLM neurons from sedentary rats also exhibit increased dendritic branching in rostral regions of the RVLM. We hypothesized that regionally specific structural neuroplasticity would manifest as enhanced SSNA but not LSNA following activation of the rostral RVLM. To test this hypothesis, groups of physically active (10–12 weeks on running wheels) or sedentary, male Sprague-Dawley rats were instrumented to record mean arterial pressure, LSNA and SSNA under Inactin anesthesia and during microinjections of glutamate (30 nl, 10 mM) into multiple sites within the RVLM. Sedentary conditions enhanced SSNA but not LSNA responses and SSNA responses were enhanced at more central and rostral sites. Results suggest that enhanced SSNA responses in rostral RVLM coincide with enhanced dendritic branching in rostral RVLM observed previously. Identifying structural and functional neuroplasticity in specific populations of RVLM neurons may help identify new treatments for cardiovascular diseases, known to be more prevalent in sedentary individuals.
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Affiliation(s)
- Madhan Subramanian
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| | - Patrick J Mueller
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
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Silva FC, de Menezes RC, Chianca DA. The implication of protein malnutrition on cardiovascular control systems in rats. Front Physiol 2015; 6:246. [PMID: 26388783 PMCID: PMC4557349 DOI: 10.3389/fphys.2015.00246] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 08/17/2015] [Indexed: 01/01/2023] Open
Abstract
The malnutrition in early life is associated with metabolic changes and cardiovascular impairment in adulthood. Deficient protein intake-mediated hypertension has been observed in clinical and experimental studies. In rats, protein malnutrition also increases the blood pressure and enhances heart rate and sympathetic activity. In this review, we discuss the effects of post-weaning protein malnutrition on the resting mean arterial pressure and heart rate and their variabilities, cardiovascular reflexes sensitivity, cardiac autonomic balance, sympathetic and renin-angiotensin activities and neural plasticity during adult life. These insights reveal an interesting prospect on the autonomic modulation underlying the cardiovascular imbalance and provide relevant information on preventing cardiovascular diseases.
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Affiliation(s)
- Fernanda C Silva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil ; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto Ouro Preto, Brazil
| | - Rodrigo C de Menezes
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil ; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto Ouro Preto, Brazil
| | - Deoclécio A Chianca
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil ; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto Ouro Preto, Brazil
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Minic Z, O'Leary DS, Scislo TJ. Nucleus tractus solitarii A(2a) adenosine receptors inhibit cardiopulmonary chemoreflex control of sympathetic outputs. Auton Neurosci 2013; 180:32-42. [PMID: 24216055 DOI: 10.1016/j.autneu.2013.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/03/2013] [Accepted: 10/16/2013] [Indexed: 01/18/2023]
Abstract
Previously we have shown that stimulation of inhibitory A1 adenosine receptors located in the nucleus tractus solitarii (NTS) attenuates cardiopulmonary chemoreflex (CCR) evoked inhibition of renal, adrenal and lumbar sympathetic nerve activity and reflex decreases in arterial pressure and heart rate. Activation of facilitatory A2a adenosine receptors, which dominate over A1 receptors in the NTS, contrastingly alters baseline activity of regional sympathetic outputs: it decreases renal, increases adrenal and does not change lumbar nerve activity. Considering that NTS A2a receptors may facilitate release of inhibitory transmitters we hypothesized that A2a receptors will act in concert with A1 receptors differentially inhibiting regional sympathetic CCR responses (adrenal>lumbar>renal). In urethane/chloralose anesthetized rats (n=38) we compared regional sympathetic responses evoked by stimulation of the CCR with right atrial injections of serotonin 5HT3 receptor agonist, phenylbiguanide, (1-8μg/kg) before and after selective stimulation, blockade or combined blockade and stimulation of NTS A2a adenosine receptors (microinjections into the NTS of CGS-21680 0.2-20pmol/50nl, ZM-241385 40pmol/100nl or ZM-241385+CGS-21680, respectively). We found that stimulation of A2a adenosine receptors uniformly inhibited the regional sympathetic and hemodynamic reflex responses and this effect was abolished by the selective blockade of NTS A2a receptors. This indicates that A2a receptor triggered inhibition of CCR responses and the contrasting shifts in baseline sympathetic activity are mediated via different mechanisms. These data implicate that stimulation of NTS A2a receptors triggers unknown inhibitory mechanism(s) which in turn inhibit transmission in the CCR pathway when adenosine is released into the NTS during severe hypotension.
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Affiliation(s)
- Zeljka Minic
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Donal S O'Leary
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Tadeusz J Scislo
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, United States.
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Ichinose TK, Minic Z, Li C, O'Leary DS, Scislo TJ. Activation of NTS A(1) adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex. Am J Physiol Regul Integr Comp Physiol 2012; 303:R539-50. [PMID: 22814665 DOI: 10.1152/ajpregu.00164.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously we have shown that adenosine operating via the A(1) receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it is likely that adenosine operating via A(1) receptors in the NTS may differentially inhibit regional sympathetic responses evoked by activation of cardiopulmonary chemoreceptors. Therefore, in urethane-chloralose-anesthetized rats (n = 37) we compared regional sympathoinhibition evoked by the cardiopulmonary chemoreflex (activated with right atrial injections of serotonin 5HT(3) receptor agonist phenylbiguanide, PBG, 1-8 μg/kg) before and after selective stimulation of NTS A(1) adenosine receptors [microinjections of N(6)-cyclopentyl adenosine (CPA), 0.033-330 pmol/50 nl]. Activation of cardiopulmonary chemoreceptors evoked differential, dose-dependent sympathoinhibition (RSNA>ASNA>LSNA), and decreases in arterial pressure and heart rate. These differential sympathetic responses were uniformly attenuated in dose-dependent manner by microinjections of CPA into the NTS. Volume control (n = 11) and blockade of adenosine receptor subtypes in the NTS via 8-(p-sulfophenyl)theophylline (8-SPT, 1 nmol in 100 nl) (n = 9) did not affect the reflex responses. We conclude that activation of NTS A(1) adenosine receptors uniformly inhibits neural and cardiovascular cardiopulmonary chemoreflex responses. A(1) adenosine receptors have no tonic modulatory effect on this reflex under normal conditions. However, when adenosine is released into the NTS (i.e., during stress or severe hypotension/ischemia), it may serve as negative feedback regulator for depressor and sympathoinhibitory reflexes integrated in the NTS.
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Affiliation(s)
- Tomoko K Ichinose
- Department of Physiology, Wayne State University School of Medicine Detroit, Detroit, MI 48201, USA
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Mueller PJ, Mischel NA, Scislo TJ. Differential activation of adrenal, renal, and lumbar sympathetic nerves following stimulation of the rostral ventrolateral medulla of the rat. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1230-40. [PMID: 21346240 DOI: 10.1152/ajpregu.00713.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Under acute and chronic conditions, the sympathetic nervous system can be activated in a differential and even selective manner. Activation of the rostral ventrolateral medulla (RVLM) has been implicated in differential control of sympathetic outputs based on evidence primarily in the cat. Although several studies indicate that differential control of sympathetic outflow occurs in other species, only a few studies have addressed whether the RVLM is capable of producing varying patterns of sympathetic activation in the rat. Therefore, the purpose of the present study was to determine whether activation of the RVLM results in simultaneous and differential increases in preganglionic adrenal (pre-ASNA), renal (RSNA), and lumbar (LSNA) sympathetic nerve activities. In urethane-chloralose anesthetized rats, pre-ASNA, RSNA, and LSNA were recorded simultaneously in all animals. Microinjections of selected concentrations and volumes of glutamate increased pre-ASNA, RSNA, and LSNA concurrently and differentially. Pre-ASNA and RSNA (in most cases) exhibited greater increases compared with LSNA on a percentage basis. By varying the volume or location of the glutamate microinjections, we also identified individual examples of differential and selective activation of these nerves. Decreases in arterial pressure or bilateral blockade of RVLM GABA(A) receptors also revealed differential activation, with the latter having a 3- to 4-fold greater effect on sympathetic activity. Our data provide evidence that activation of the rat RVLM increases renal, lumbar, and preganglionic adrenal sympathetic nerve activities concurrently, differentially, and, in some cases, selectively.
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Affiliation(s)
- Patrick J Mueller
- Dept. of Physiology, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA.
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Bezerra VM, Xavier CH, Fernandes LG, Cardoso LM, Fontes MAP, Chianca DA. Sympathoinhibition to Bezold–Jarisch reflex is attenuated in protein malnourished rats. Neurosci Lett 2011; 488:129-32. [DOI: 10.1016/j.neulet.2010.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/01/2010] [Accepted: 11/02/2010] [Indexed: 01/13/2023]
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Zhong MK, Shi Z, Zhou LM, Gao J, Liao ZH, Wang W, Gao XY, Zhu GQ. Regulation of cardiac sympathetic afferent reflex by GABAAand GABABreceptors in paraventricular nucleus in rats. Eur J Neurosci 2008; 27:3226-32. [DOI: 10.1111/j.1460-9568.2008.06261.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ditting T, Hilgers KF, Stetter A, Linz P, Schönweiss C, Veelken R. Renal sympathetic nerves modulate erythropoietin plasma levels after transient hemorrhage in rats. Am J Physiol Renal Physiol 2007; 293:F1099-106. [PMID: 17634394 DOI: 10.1152/ajprenal.00267.2007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In contrast to other sympathetic outflow tracts, renal sympathetic nerve activity (RSNA) decreases in response to hypotensive hemorrhage. The functional significance of this "paradox" is not known. We tested the hypothesis that RSNA modulates renal perfusion and thus erythropoietin (EPO) release after transient hypotensive hemorrhage in anesthetized rats. Plasma EPO was measured before and after 30 min of transient hypotensive hemorrhage (i.e., -40 mmHg from mean baseline blood pressure, followed by reinfusion of shed blood) and 120 min thereafter in sham-denervated rats, and after renal denervation (DNX) or bilateral cervical vagotomy (VX) to abolish/blunt the RSNA decrease mediated by a cardiopulmonary reflex. RSNA, renal Doppler flow, renal vascular resistance (RVR), resistance index, and oxygen delivery/uptake (Do(2)/Vo(2)) were measured. RSNA decreased in intact animals (-40 +/- 5% from baseline, P < 0.05). This was blunted by VX. With intact nerves, EPO level did not increase. In DNX rats, EPO was increased at minute 120 (49 +/- 3 vs. 74 +/- 2 mU/ml; P < 0.05), in VX rats this (47 +/- 2 vs. 62 +/- 4 mU/ml; P < 0.05) was less pronounced. Do(2) in DNX rats was lower compared with intact and VX rats (0.25 +/- 0.04 vs. 0.51 +/- 0.06 and 0.54 +/- 0.05 ml O(2)/min; P < 0.05) due to lower Doppler flow and increased RVR. RVR and Do(2) were similar in intact and VX rats, but resistance index differed between all groups (0.70 +/- 0.02 vs. 0.78 +/- 0.02 vs. 0.85 +/- 0.02; P < 0.05, intact vs. VX vs. DNX), indicating differential reactivity of renal vasculature. Vo(2) was unaffected by VX and DNX. Renal sympathoinhibition during hypotensive hemorrhage might help to preserve sufficient oxygenation of renal tissue by modulation of hemodynamic mechanisms that act to adapt renal oxygen availability to demand.
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Affiliation(s)
- Tilmann Ditting
- Department of Nephrology, Friedrich-Alexander-Univ. Erlangen-Nürnberg, Erlangen, Germany
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