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Sharma NM, Haibara AS, Katsurada K, Nandi SS, Liu X, Zheng H, Patel KP. Central Ang II (Angiotensin II)-Mediated Sympathoexcitation: Role for HIF-1α (Hypoxia-Inducible Factor-1α) Facilitated Glutamatergic Tone in the Paraventricular Nucleus of the Hypothalamus. Hypertension 2020; 77:147-157. [PMID: 33296248 PMCID: PMC7720881 DOI: 10.1161/hypertensionaha.120.16002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Central infusion of Ang II (angiotensin II) has been associated with increased sympathetic outflow resulting in neurogenic hypertension. In the present study, we appraised whether the chronic increase in central Ang II activates the paraventricular nucleus of the hypothalamus (PVN) resulting in elevated sympathetic tone and altered baro- and chemoreflexes. Further, we evaluated the contribution of HIF-1α (hypoxia-inducible factor-1α), a transcription factor involved in enhancing the expression of N-methyl-D-aspartate receptors and thus glutamatergic-mediated sympathetic tone from the PVN. Ang II infusion (20 ng/minute, intracerebroventricular, 14 days) increased mean arterial pressure (126±9 versus 84±4 mm Hg), cardiac sympathetic tone (96±7 versus 75±6 bpm), and decreased cardiac parasympathetic tone (16±2 versus 36±3 versus bpm) compared with saline-infused controls in conscious rats. The Ang II-infused group also showed an impaired baroreflex control of heart rate (-1.50±0.1 versus -2.50±0.3 bpm/mm Hg), potentiation of the chemoreflex pressor response (53±7 versus 30±7 mm Hg) and increased number of FosB-labeled cells (53±3 versus 19±4) in the PVN. Concomitant with the activation of the PVN, there was an increased expression of HIF-1α and N-Methyl-D-Aspartate-type1 receptors in the PVN. Further, Ang II-infusion showed increased renal sympathetic nerve activity (20.5±2.3% versus 6.4±1.9% of Max) and 3-fold enhanced renal sympathetic nerve activity responses to microinjection of N-methyl-D-aspartate (200 pmol) into the PVN of anesthetized rats. Further, silencing of HIF-1α in NG108 cells abrogated the expression of N-methyl-D-aspartate-N-methyl-D-aspartate-type1 induced by Ang II. Taken together, our studies suggest a novel Ang II-HIF-1α-N-methyl-D-aspartate receptor-mediated activation of preautonomic neurons in the PVN, resulting in increased sympathetic outflow and alterations in baro- and chemoreflexes.
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Affiliation(s)
- Neeru M Sharma
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (N.M.S., A.S.H., K.K., S.S.N., K.P.P.)
| | - Andréa S Haibara
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (N.M.S., A.S.H., K.K., S.S.N., K.P.P.)
| | - Kenichi Katsurada
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (N.M.S., A.S.H., K.K., S.S.N., K.P.P.)
| | - Shyam S Nandi
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (N.M.S., A.S.H., K.K., S.S.N., K.P.P.)
| | - Xuefei Liu
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion (X.L., H.Z.)
| | - Hong Zheng
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion (X.L., H.Z.)
| | - Kaushik P Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (N.M.S., A.S.H., K.K., S.S.N., K.P.P.)
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Guo Q, Feng X, Xue H, Jin S, Teng X, Duan X, Xiao L, Wu Y. Parental Renovascular Hypertension-Induced Autonomic Dysfunction in Male Offspring Is Improved by Prenatal or Postnatal Treatment With Hydrogen Sulfide. Front Physiol 2019; 10:1184. [PMID: 31607943 PMCID: PMC6761249 DOI: 10.3389/fphys.2019.01184] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/02/2019] [Indexed: 12/18/2022] Open
Abstract
Increasing evidence indicates there is a strong association between parental health during pregnancy and incidence of cardiovascular disease in adult offspring. Recently, hydrogen sulfide (H2S) has been demonstrated to be a powerful vasodilator of the placental vasculature, improving intrauterine growth restriction. In this study, we investigated whether parental hypertension induces autonomic dysfunction in male adult offspring, and the H2S mechanism underlying this autonomic dysfunction. 2-kidney-1-clip method was employed to induce parental hypertension during pregnancy and lactation in rats. Basal blood pressure (BP) and autonomic function of male offspring in adulthood was evaluated. Additionally, either maternal hypertensive dams or their male offspring after weaning were treated with H2S to determine improving effects of H2S on autonomic dysfunction. The BP was significantly increased in male offspring of renovascular hypertensive dams when compared to that in offspring of normotensive dams. The offspring of renovascular hypertensive dams also exhibited blunted baroreflex sensitivity, increased sympathetic effect and sympathetic tonus. Western blotting analysis revealed downregulation of endogenous H2S catalyzed enzyme and upregulation of angiotensin Ang II type 1 receptor (AT1R) pathway in the nucleus tractus solitarius and rostral ventrolateral medulla, two hindbrain nuclei involved in BP and autonomic regulation, in these offspring. Either prenatal or postnatal treatment with H2S improved the adverse effects. The results suggest that parental hypertension results in elevated BP and autonomic dysfunction in adult male offspring through activation of AT1R pathway and inhibition of endogenous H2S production in the brain.
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Affiliation(s)
- Qi Guo
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Xiaohong Feng
- Department of Laboratory Diagnostics, Hebei Medical University, Shijiazhuang, China
| | - Hongmei Xue
- Department of Physiology, Hebei Medical University, Shijiazhuang, China.,Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, China
| | - Sheng Jin
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Xu Teng
- Department of Physiology, Hebei Medical University, Shijiazhuang, China.,Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, China
| | - Xiaocui Duan
- Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, China
| | - Lin Xiao
- Department of Physiology, Hebei Medical University, Shijiazhuang, China.,Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, China
| | - Yuming Wu
- Department of Physiology, Hebei Medical University, Shijiazhuang, China.,Hebei Collaborative Innovation Center for Cardio-Cerebrovascular Disease, Shijiazhuang, China.,Key Laboratory of Vascular Medicine of Hebei Province, Shijiazhuang, China
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Huber G, Schuster F, Raasch W. Brain renin-angiotensin system in the pathophysiology of cardiovascular diseases. Pharmacol Res 2017; 125:72-90. [PMID: 28687340 DOI: 10.1016/j.phrs.2017.06.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 02/07/2023]
Abstract
Cardiovascular diseases (CVD) are among the main causes of death globally and in this context hypertension represents one of the key risk factors for developing a CVD. It is well established that the peripheral renin-angiotensin system (RAS) plays an important role in regulating blood pressure (BP). All components of the classic RAS can also be found in the brain but, in contrast to the peripheral RAS, how the endogenous RAS is involved in modulating cardiovascular effects in the brain is not fully understood yet. It is a complex system that may work differently in diverse areas of the brain and is linked to the peripheral system by the circumventricular organs (CVO), which do not have a blood brain barrier (BBB). In this review, we focus on the brain angiotensin peptides, their interactions with each other, and the consequences in the central nervous system (CNS) concerning cardiovascular control. Additionally, we present potential drug targets in the brain RAS for the treatment of hypertension.
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Affiliation(s)
- Gianna Huber
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany; CBBM (Center of Brain, Behavior and Metabolism), Lübeck, Germany
| | - Franziska Schuster
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany; CBBM (Center of Brain, Behavior and Metabolism), Lübeck, Germany
| | - Walter Raasch
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany; CBBM (Center of Brain, Behavior and Metabolism), Lübeck, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany.
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Ogier M, Bricca G, Bader M, Bezin L. Locus Coeruleus Dysfunction in Transgenic Rats with Low Brain Angiotensinogen. CNS Neurosci Ther 2016; 22:230-7. [PMID: 26775713 DOI: 10.1111/cns.12488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/30/2015] [Accepted: 10/30/2015] [Indexed: 12/25/2022] Open
Abstract
AIMS Transgenic TGR(ASrAOGEN)680 (TGR) rats with specific downregulation of glial angiotensinogen (AOGEN) synthesis develop cardiovascular deficits, anxiety, altered response to stress, and depression. Here, we evaluated whether these deficits are associated with alteration of the integrity of the noradrenergic system originating from locus coeruleus (LC) neurons. METHODS Adult TGR rats were compared to control Sprague Dawley rats in terms of the following: tissue levels of transcripts encoding noradrenergic markers, tissue tyrosine hydroxylase (TH) protein level, in vivo TH activity, density of TH-containing fibers, behavioral response to novelty, locomotor activity, and polysomnography. RESULTS TH expression was increased in the LC of TGR rats compared to controls. In LC terminal fields, there was an increase in density of TH-containing fibers in TGR rats that was associated with an elevation of in vivo TH activity. TGR rats also displayed locomotor hyperactivity in response to novelty. Moreover, polysomnographic studies indicated that daily paradoxical sleep duration was increased in TGR rats and that the paradoxical sleep rebound triggered by total sleep deprivation was blunted in these rats. CONCLUSIONS Altogether, these results suggest that disruption of astroglial AOGEN synthesis leads to cardiovascular, cognitive, behavioral, and sleep disorders that might be partly due to LC dysfunction.
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Affiliation(s)
- Michael Ogier
- INSERM U1028, CNRS UMR5292, University Claude Bernard Lyon 1, Lyon Neuroscience Research Center, Team TIGER, Lyon, France.,Institute for Epilepsy, IDEE, Lyon, France.,French Armed Forces Biomedical Research Institute, Bretigny-sur-Orge, France
| | | | - Michael Bader
- Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Laurent Bezin
- INSERM U1028, CNRS UMR5292, University Claude Bernard Lyon 1, Lyon Neuroscience Research Center, Team TIGER, Lyon, France.,Institute for Epilepsy, IDEE, Lyon, France
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Santos CFF, Santos SHS, Ferreira AVM, Botion LM, Santos RAS, Campagnole-Santos MJ. Association of an oral formulation of angiotensin-(1-7) with atenolol improves lipid metabolism in hypertensive rats. Peptides 2013; 43:155-9. [PMID: 23517878 DOI: 10.1016/j.peptides.2013.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/11/2013] [Accepted: 03/11/2013] [Indexed: 11/18/2022]
Abstract
The β-adrenergic blockers and antagonists of the renin-angiotensin system (RAS) are among the drugs that present better results in the control of cardio-metabolic diseases. The aim of the present study was to evaluate the effect of the association of the β-blocker, atenolol, and an oral formulation of Ang-(1-7) on lipid metabolism in spontaneously hypertensive rats (SHR). The main results showed that SHR treated with oral formulation of Ang-(1-7) in combination to atenolol have an improvement of lipid metabolism with a reduction of total plasma cholesterol, improvement of oral fat load tolerance and an increase in the lipolytic response stimulated by the β-adrenergic agonist, isoproterenol, without modification of resting glucose or insulin sensitivity in adipocytes. In conclusion, we showed that administration of an Ang-(1-7) oral formulation in association with a β-blocker induces beneficial effects on dyslipidemia treatment associated with hypertension.
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Affiliation(s)
- Cynthia F F Santos
- National Institute of Science and Technology (INCT-NanoBiofar), Department of Physiology and Biophysics, Biological Sciences Institute, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Abstract
Aging is associated with an imbalance in sympathetic and parasympathetic outflow to cardiovascular effector organs. This autonomic imbalance contributes to the decline in cardiovagal baroreceptor reflex function during aging, which allows for unrestrained activation of the sympathetic nervous system to negatively impact resting systolic blood pressure and its variability. Further, impaired baroreflex function can contribute to the development of insulin resistance and other features of the metabolic syndrome during aging through overlap in autonomic neural pathways that regulate both cardiovascular and metabolic functions. Increasing evidence supports a widespread influence of the renin-angiotensin system (RAS) on both sympathetic and parasympathetic activity through receptors distributed to peripheral and central sites of action. Indeed, therapeutic interventions to block the RAS are well established for the treatment of hypertension in elderly patients, and reduce the incidence of new-onset diabetes in clinical trials. Further, RAS blockade increases lifespan and improves numerous age-related pathologies in rodents, often independent of blood pressure. The beneficial effects of these interventions are at least in part attributed to suppression of angiotensin II formed locally within the brain. In particular, recent insights from transgenic rodents provide evidence that long-term alteration in the brain RAS modulates the balance between angiotensin II and angiotensin-(1-7), and related intracellular signaling pathways, to influence cardiovascular and metabolic function in the context of hypertension and aging.
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Arnold AC, Sakima A, Kasper SO, Vinsant S, Garcia-Espinosa MA, Diz DI. The brain renin-angiotensin system and cardiovascular responses to stress: insights from transgenic rats with low brain angiotensinogen. J Appl Physiol (1985) 2012; 113:1929-36. [PMID: 22984245 DOI: 10.1152/japplphysiol.00569.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renin-angiotensin system (RAS) has been identified as an attractive target for the treatment of stress-induced cardiovascular disorders. The effects of angiotensin (ANG) peptides during stress responses likely result from an integration of actions by circulating peptides and brain peptides derived from neuronal and glial sources. The present review focuses on the contribution of endogenous brain ANG peptides to pathways involved in cardiovascular responses to stressors. During a variety of forms of stress, neuronal pathways in forebrain areas containing ANG II or ANG-(1-7) are activated to stimulate descending angiotensinergic pathways that increase sympathetic outflow to increase blood pressure. We provide evidence that glia-derived ANG peptides influence brain AT(1) receptors. This appears to result in modulation of the responsiveness of the neuronal pathways activated during stressors that elevate circulating ANG peptides to activate brain pathways involving descending hypothalamic projections. It is well established that increased cardiovascular reactivity to stress is a significant predictor of hypertension and other cardiovascular diseases. This review highlights the importance of understanding the impact of RAS components from the circulation, neurons, and glia on the integration of cardiovascular responses to stressors.
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Affiliation(s)
- Amy C Arnold
- The Hypertension & Vascular Research Center and the Departments of General Surgery and Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157-1032, USA
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Cardiovascular responses evoked by activation or blockade of GABAA receptors in the hypothalamic PVN are attenuated in transgenic rats with low brain angiotensinogen. Brain Res 2012; 1448:101-10. [DOI: 10.1016/j.brainres.2012.02.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 01/25/2012] [Accepted: 02/09/2012] [Indexed: 11/24/2022]
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Baltatu OC, Campos LA, Bader M. Local renin-angiotensin system and the brain--a continuous quest for knowledge. Peptides 2011; 32:1083-6. [PMID: 21333703 DOI: 10.1016/j.peptides.2011.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 02/10/2011] [Indexed: 01/22/2023]
Abstract
The ancient renin-angiotensin system (RAS) was discovered more than a hundred years ago by identifying the rate-limiting enzyme of the system and its relevance to blood pressure regulation. Forty years ago, Detlev Ganten et al. postulated the existence of a tissue RAS. In these forty years, he kept developing the knowledge of these systems either directly or by training or attracting the interest of many researchers. Through the present review, we try to highlight recent advancements that originated from the postulation of local brain RAS. Although a large amount of knowledge accumulated, this system continues to intrigue and stimulate the interest and imagination of many researchers.
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Affiliation(s)
- Ovidiu C Baltatu
- Center of Biomedical Engineering, University Camilo Castelo Branco, Rod. Presidente Dutra Km 138, SP, 12247-004 São José dos Campos, Brazil
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Garcia-Espinosa MA, Shaltout HA, Olson J, Westwood BM, Robbins ME, Link K, Diz DI. Proton magnetic resonance spectroscopy detection of neurotransmitters in dorsomedial medulla correlate with spontaneous baroreceptor reflex function. Hypertension 2010; 55:487-93. [PMID: 20065146 DOI: 10.1161/hypertensionaha.109.145722] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Control of heart rate variability via modulation of sympathovagal balance is a key function of nucleus tractus solitarii and the dorsal motor nucleus of the vagus localized in the dorsomedial medulla oblongata. Normal blood pressure regulation involves precise balance of glutamate (Glu)-glutamine-gamma-aminobutyric acid transmitter systems, and angiotensin II modulates these transmitters to produce tonic suppression of reflex function. It is not known, however, whether other brain transmitters/metabolites are indicators of baroreflex function. This study establishes the concept that comprehensive baseline transmitter/metabolite profiles obtained using in vivo (1)H magnetic resonance spectroscopy in rats with well-characterized differences in resting blood pressure and baroreflex function can be used as indices of autonomic balance or baroreflex sensitivity. Transgenic rats with over-expression of renin [m(Ren2)27] or under-expression of glial-angiotensinogen (ASrAogen) were compared with Sprague-Dawley rats. Glu concentration in the dorsal medulla is significantly higher in ASrAogen rats compared with either Sprague-Dawley or (mRen2)27 rats. Glu levels and the ratio of Glu:glutamine correlated positively with indices of higher vagal tone consistent with the importance of these neurotransmitters in baroreflex function. Interestingly, the levels of choline-containing metabolites showed a significant positive correlation with spontaneous baroreflex sensitivity and a negative correlation with sympathetic tone. Thus, we demonstrate the concept that noninvasive assessment of neurochemical biomarkers may be used as an index of baroreflex sensitivity.
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Affiliation(s)
- Maria A Garcia-Espinosa
- Department of Radiation Oncology, Wake Forest University School of Medicine, Hypertension and Vascular Research Center, Winston-Salem, NC 27157-1032, USA.
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Arnold AC, Shaltout HA, Gallagher PE, Diz DI. Leptin impairs cardiovagal baroreflex function at the level of the solitary tract nucleus. Hypertension 2009; 54:1001-8. [PMID: 19770402 DOI: 10.1161/hypertensionaha.109.138065] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Circulating leptin is elevated in some forms of obesity-related hypertension, associated with impaired baroreflex function. Leptin receptors are present on vagal afferent fibers and neurons within the solitary tract nucleus, providing an anatomic distribution consistent with baroreflex modulation. Although solitary tract nucleus microinjection of 144 fmol/60 nL of leptin had no significant effect on baroreflex sensitivity for control of the heart rate in urethane/chloralose-anesthetized Sprague-Dawley rats, 500 fmol of leptin impaired baroreflex sensitivity for bradycardia in response to increases in pressure (1.15+/-0.04 versus 0.52+/-0.12 ms/mm Hg; P<0.01). Transgenic ASrAOGEN rats with low brain angiotensinogen have an upregulation of the leptin receptor and p85 alpha mRNA in the dorsal medulla relative to Sprague-Dawley rats. Consistent with these observations, the response to leptin was enhanced in ASrAOGEN rats, because both the 144-fmol (1.46+/-0.08 versus 0.75+/-0.10 ms/mm Hg; P<0.001) and 500-fmol (1.36+/-0.32 versus 0.44+/-0.06 ms/mm Hg; P<0.05) leptin microinjections impaired baroreflex sensitivity. At these doses, leptin microinjection had no effect on resting pressure, heart rate, or the tachycardic response to decreases in pressure in Sprague-Dawley or ASrAOGEN rats. Thus, exogenous leptin at sites within the solitary tract nucleus impairs the baroreflex sensitivity for bradycardia induced by increases in arterial pressure, consistent with a permissive role in mediating increases in arterial pressure. Baroreflex inhibition was enhanced in animals with evidence of increased leptin receptor and relevant signaling pathway mRNA.
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Affiliation(s)
- Amy C Arnold
- Hypertension and Vascular Research Center and Physiology and Pharmacology Department, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA
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