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Adrenomedullin in paraventricular nucleus attenuates adipose afferent reflex and sympathoexcitation via receptors mediated nitric oxide-gamma-aminobutyric acid A type receptor pathway in rats with obesity-related hypertension. J Hypertens 2023; 41:233-245. [PMID: 36583351 DOI: 10.1097/hjh.0000000000003301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Hypothalamic paraventricular nucleus (PVN) is an important central site for the control of the adipose afferent reflex (AAR) that increases sympathetic outflow and blood pressure in obesity-related hypertension (OH). METHOD In this study, we investigated the effects of nitric oxide (NO) and cardiovascular bioactive polypeptide adrenomedullin (ADM) in the PVN on AAR and sympathetic nerve activity (SNA) in OH rats induced by a high-fat diet. RESULTS The results showed that ADM, total neuronal NO synthase (nNOS) and phosphorylated-nNOS protein expression levels in the PVN of the OH rats were down-regulated compared to the control rats. The enhanced AAR in OH rats was attenuated by PVN acute application of NO donor sodium nitroprusside (SNP), but was strengthened by the nNOS inhibitor nNOS-I, guanylyl cyclase inhibitor (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) and gamma-aminobutyric acid A type receptor (GABAA) antagonist Bicuculline. Moreover, PVN ADM microinjection not only decreased basal SNA but also attenuated the enhanced AAR in OH rats, which were effectively inhibited by ADM receptor antagonist ADM22-52, nNOS-I, ODQ or Bicuculline pretreatment. Bilateral PVN acute microinjection of ADM also caused greater increases in NO and cyclic guanosine monophosphate (cGMP) levels, and nNOS phosphorylation. Adeno-associated virus vectors encoding ADM (AAV-ADM) transfection in the PVN of OH rats not only decreased the elevated AAR, basal SNA and blood pressure (BP), but also increased the expression and activation of nNOS. Furthermore, AAV-ADM transfection improved vascular remodeling in OH rats. CONCLUSION Taken together, our data highlight the roles of ADM in improving sympathetic overactivation, enhanced AAR and hypertension, and its related mechanisms associated with receptors mediated NO-cGMP-GABAA pathway in OH condition.
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Wen S, Nguyen T, Gong M, Yuan X, Wang C, Jin J, Zhou L. An Overview of Similarities and Differences in Metabolic Actions and Effects of Central Nervous System Between Glucagon-Like Peptide-1 Receptor Agonists (GLP-1RAs) and Sodium Glucose Co-Transporter-2 Inhibitors (SGLT-2is). Diabetes Metab Syndr Obes 2021; 14:2955-2972. [PMID: 34234493 PMCID: PMC8254548 DOI: 10.2147/dmso.s312527] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/15/2021] [Indexed: 12/17/2022] Open
Abstract
GLP-1 receptor agonists (GLP-1RAs) and SGLT-2 inhibitors (SGLT-2is) are novel antidiabetic medications associated with considerable cardiovascular benefits therapying treatment of diabetic patients. GLP-1 exhibits atherosclerosis resistance, whereas SGLT-2i acts to ameliorate the neuroendocrine state in the patients with chronic heart failure. Despite their distinct modes of action, both factors share pathways by regulating the central nervous system (CNS). While numerous preclinical and clinical studies have demonstrated that GLP-1 can access various nuclei associated with energy homeostasis and hedonic eating in the CNS via blood-brain barrier (BBB), research on the activity of SGLT-2is remains limited. In our previous studies, we demonstrated that both GLP-1 receptor agonists (GLP-1RAs) liraglutide and exenatide, as well as an SGLT-2i, dapagliflozin, could activate various nuclei and pathways in the CNS of Sprague Dawley (SD) rats and C57BL/6 mice, respectively. Moreover, our results revealed similarities and differences in neural pathways, which possibly regulated different metabolic effects of GLP-1RA and SGLT-2i via sympathetic and parasympathetic systems in the CNS, such as feeding, blood glucose regulation and cardiovascular activities (arterial blood pressure and heart rate control). In the present article, we extensively discuss recent preclinical studies on the effects of GLP-1RAs and SGLT-2is on the CNS actions, with the aim of providing a theoretical explanation on their mechanism of action in improvement of the macro-cardiovascular risk and reducing incidence of diabetic complications. Overall, these findings are expected to guide future drug design approaches.
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Affiliation(s)
- Song Wen
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Thiquynhnga Nguyen
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Min Gong
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Xinlu Yuan
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Chaoxun Wang
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Jianlan Jin
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
| | - Ligang Zhou
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of China
- Shanghai Key Laboratory of Vascular Lesions Regulation and Remodeling, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, People’s Republic of China
- Correspondence: Ligang Zhou Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, People’s Republic of ChinaTel +8613611927616 Email
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Geng Z, Ye C, Tong Y, Zhang F, Zhou YB, Xiong XQ. Exacerbated pressor and sympathoexcitatory effects of central Elabela in spontaneously hypertensive rats. Am J Physiol Heart Circ Physiol 2019; 318:H124-H134. [PMID: 31834836 DOI: 10.1152/ajpheart.00449.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Elabela (ELA) is a newly discovered peptide that acts as a novel endogenous ligand of angiotensin receptor-like 1 (APJ) receptor. This study was designed to evaluate the effects of ELA-21 in paraventricular nucleus (PVN) on blood pressure and sympathetic nerve activity in spontaneously hypertensive rats (SHR). Experiments were performed in male Wistar-Kyoto rats (WKY) and SHR. ELA expression was upregulated in PVN of SHR. PVN microinjection of ELA-21 increased renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP), heart rate (HR), plasma norepinephrine, and arginine vasopressin (AVP) levels in SHR. Intravenous injection of ELA-21 significantly decreased MAP and HR in both WKY and SHR, but only induced a slight decrease in RSNA. APJ antagonist F13A in PVN abolished the effects of ELA-21 on RSNA, MAP and HR. Intravenous infusion of both ganglionic blocker hexamethonium and AVP V1a receptor antagonist SR49059 caused significant reduction in the effects of ELA-21 on RSNA, MAP and HR in SHR, while combined administration of hexamethonium and SR49059 abolished the effects of ELA-21. ELA-21 microinjection stimulated Akt and p85α subunit of phosphatidylinositol 3-kinase (PI3K) phosphorylation in PVN, whereas PI3K inhibitor LY294002 or Akt inhibitor MK-2206 almost abolished the effects of ELA-21 on RSNA, MAP, and HR. Chronic PVN infusion of ELA-21 induced sympathetic activation, hypertension, and AVP release accompanied with cardiovascular remodeling in normotensive WKY. In conclusion, ELA-21 in PVN induces exacerbated pressor and sympathoexcitatory effects in hypertensive rats via PI3K-Akt pathway.NEW & NOTEWORTHY We demonstrated that PVN microinjection of ELA-21 increases sympathetic nerve activity and blood pressure, which can be abolished by pretreatment of APJ antagonist. This is the first demonstration that central ELA can induce hypertension. The pressor effects in PVN are mediated by both sympathetic activation and vasopressin release via PI3K-Akt pathway. Our data confirm that ELA is upregulated in the PVN of SHR and so may be involved in the pressor and sympathoexcitatory effects in hypertension.
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Affiliation(s)
- Zhi Geng
- Department of Cardiac Surgery, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chao Ye
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ying Tong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Feng Zhang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ye-Bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiao-Qing Xiong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
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Kang Y, Ding L, Dai H, Wang F, Zhou H, Gao Q, Xiong X, Zhang F, Song T, Yuan Y, Zhu G, Zhou Y. Intermedin in Paraventricular Nucleus Attenuates Ang II-Induced Sympathoexcitation through the Inhibition of NADPH Oxidase-Dependent ROS Generation in Obese Rats with Hypertension. Int J Mol Sci 2019; 20:ijms20174217. [PMID: 31466304 PMCID: PMC6747263 DOI: 10.3390/ijms20174217] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 12/19/2022] Open
Abstract
Increased reactive oxygen species (ROS) induced by angiotensin II (Ang II) in the paraventricular nucleus (PVN) play a critical role in sympathetic overdrive in hypertension (OH). Intermedin (IMD), a bioactive peptide, has extensive clinically prospects in preventing and treating cardiovascular diseases. The study was designed to test the hypothesis that IMD in the PVN can inhibit the generation of ROS caused by Ang II for attenuating sympathetic nerve activity (SNA) and blood pressure (BP) in rats with obesity-related hypertension (OH). Male Sprague-Dawley rats (160-180 g) were used to induce OH by feeding of a high-fat diet (42% kcal as fat) for 12 weeks. The dynamic changes of sympathetic outflow were evaluated as the alterations of renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) responses to certain chemicals. The results showed that the protein expressions of Ang II type 1 receptor (AT1R), calcitonin receptor-like receptor (CRLR) and receptor activity-modifying protein 2 (RAMP2) and RAMP3 were markedly increased, but IMD was much lower in OH rats when compared to control rats. IMD itself microinjection into PVN not only lowered SNA, NADPH oxidase activity and ROS level, but also decreased Ang II-caused sympathetic overdrive, and increased NADPH oxidase activity, ROS levels and mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) activation in OH rats. However, those effects were mostly blocked by the adrenomedullin (AM) receptor antagonist AM22-52 pretreatment. The enhancement of SNA caused by Ang II can be significantly attenuated by the pretreatment of AT1R antagonist lorsatan, superoxide scavenger Tempol and NADPH oxidase inhibitor apocynin (Apo) in OH rats. ERK activation inhibitor U0126 in the PVN reversed Ang II-induced enhancement of SNA, and Apo and IMD pretreatment in the PVN decreased Ang II-induced ERK activation. Chronic IMD administration in the PVN resulted in significant reductions in basal SNA and BP in OH rats. Moreover, IMD lowered NADPH oxidase activity and ROS level in the PVN; reduced the protein expressions of AT1R and NADPH oxidase subunits NOX2 and NOX4, and ERK activation in the PVN; and decreased Ang II levels-inducing sympathetic overactivation. These results indicated that IMD via AM receptors in the PVN attenuates SNA and hypertension, and decreases Ang II-induced enhancement of SNA through the inhibition of NADPH oxidase activity and ERK activation.
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Affiliation(s)
- Ying Kang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Lei Ding
- Department of Pathophysiology, Xuzhou Medical University, Xuzhou 221004, China
| | - Hangbing Dai
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Fangzheng Wang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Hong Zhou
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Qing Gao
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Xiaoqing Xiong
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Feng Zhang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Tianrun Song
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Yan Yuan
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Guoqing Zhu
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Yebo Zhou
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China.
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Charles CJ, Jardine DL, Rademaker MT, Mark Richards A. Adrenomedullin 2 increases cardiac sympathetic nerve activity in parallel to heart rate in normal conscious sheep. Physiol Rep 2019; 7:e14096. [PMID: 31124323 PMCID: PMC6533176 DOI: 10.14814/phy2.14096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/19/2019] [Accepted: 03/29/2019] [Indexed: 12/04/2022] Open
Abstract
Both adrenomedullin 2 (AM2) and sympathetic nerve activity (SNA) have been shown to be involved in regulating cardiovascular activity, but whether any interaction between these two systems exists remains to be determined. In this study, we examine the effects of intravenous AM2 infusions on SNA directed toward the heart (cardiac SNA (CSNA)) in healthy sheep studied in the conscious state. In response to AM2, arterial pressure was reduced (P = 0.005) with both heart rate (P < 0.001) and cardiac output (P < 0.001) increased compared with vehicle control response. CSNA burst frequency (bursts/min) and burst area/min both increased during infusion of AM2 (both P < 0.001). However, correcting CSNA indices for concurrent heart rate changes resulted in CSNA burst incidence (bursts/100 beats) and burst area incidence (area/100 beats) being not significantly different between AM2 and control treatments. There were no significant differences demonstrated in plasma epinephrine or norepinephrine levels between the two study days. In conclusion, AM2 administered systemically to normal conscious sheep increases both CSNA and heart rate. However, correction for heart rate responses abrogates the rise in CSNA. It remains unclear whether AM2's primary effect is to act via the central nervous system to directly stimulate CSNA with resultant increase in heart rate, or to induce a rise in heart rate by other mechanisms.
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Affiliation(s)
- Christopher J. Charles
- Department of MedicineChristchurch Heart InstituteUniversity of Otago ChristchurchChristchurchNew Zealand
| | - David L. Jardine
- Department of MedicineChristchurch Heart InstituteUniversity of Otago ChristchurchChristchurchNew Zealand
| | - Miriam T. Rademaker
- Department of MedicineChristchurch Heart InstituteUniversity of Otago ChristchurchChristchurchNew Zealand
| | - A. Mark Richards
- Department of MedicineChristchurch Heart InstituteUniversity of Otago ChristchurchChristchurchNew Zealand
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Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension. Neurosci Bull 2018; 35:34-46. [PMID: 30276527 DOI: 10.1007/s12264-018-0292-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/14/2018] [Indexed: 01/11/2023] Open
Abstract
Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.
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Higashi Y, Shimizu T, Yamamoto M, Tanaka K, Yawata T, Shimizu S, Zou S, Ueba T, Yuri K, Saito M. Stimulation of brain nicotinic acetylcholine receptors activates adrenomedullary outflow via brain inducible NO synthase-mediated S-nitrosylation. Br J Pharmacol 2018; 175:3758-3772. [PMID: 30007012 DOI: 10.1111/bph.14445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/26/2018] [Accepted: 07/04/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE We have demonstrated that i.c.v.-administered (±)-epibatidine, a nicotinic ACh receptor (nAChR) agonist, induced secretion of noradrenaline and adrenaline (catecholamines) from the rat adrenal medulla with dihydro-β-erythroidin (an α4β2 nAChR antagonist)-sensitive brain mechanisms. Here, we examined central mechanisms for the (±)-epibatidine-induced responses, focusing on brain NOS and NO-mediated mechanisms, soluble GC (sGC) and protein S-nitrosylation (a posttranslational modification of protein cysteine thiol groups), in urethane-anaesthetized (1.0 g·kg-1 , i.p.) male Wistar rats. EXPERIMENTAL APPROACH (±)-Epibatidine was i.c.v. treated after i.c.v. pretreatment with each inhibitor described below. Then, plasma catecholamines were measured electrochemically after HPLC. Immunoreactivity of S-nitrosylated cysteine (SNO-Cys) in α4 nAChR subunit (α4)-positive spinally projecting neurones in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of adrenomedullary outflow) after i.c.v. (±)-epibatidine administration was also investigated. KEY RESULTS (±)-Epibatidine-induced elevation of plasma catecholamines was significantly attenuated by L-NAME (non-selective NOS inhibitor), carboxy-PTIO (NO scavenger), BYK191023 [selective inducible NOS (iNOS) inhibitor] and dithiothreitol (thiol-reducing reagent), but not by 3-bromo-7-nitroindazole (selective neuronal NOS inhibitor) or ODQ (sGC inhibitor). (±)-Epibatidine increased the number of spinally projecting PVN neurones with α4- and SNO-Cys-immunoreactivities, and this increment was reduced by BYK191023. CONCLUSIONS AND IMPLICATIONS Stimulation of brain nAChRs can induce elevation of plasma catecholamines through brain iNOS-derived NO-mediated protein S-nitrosylation in rats. Therefore, brain nAChRs (at least α4β2 subtype) and NO might be useful targets for alleviation of catecholamines overflow induced by smoking.
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Affiliation(s)
- Youichirou Higashi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Masaki Yamamoto
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Kenjiro Tanaka
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Toshio Yawata
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Suo Zou
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Tetsuya Ueba
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Kazunari Yuri
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
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Lu QB, Sun J, Kang Y, Sun HJ, Wang HS, Wang Y, Zhu GQ, Zhou YB. Superoxide Anions and NO in the Paraventricular Nucleus Modulate the Cardiac Sympathetic Afferent Reflex in Obese Rats. Int J Mol Sci 2017; 19:ijms19010059. [PMID: 29280941 PMCID: PMC5796009 DOI: 10.3390/ijms19010059] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 12/03/2017] [Accepted: 12/20/2017] [Indexed: 12/17/2022] Open
Abstract
This study was conducted to explore the hypothesis that the endogenous superoxide anions (O2−) and nitric oxide (NO) system of the paraventricular nucleus (PVN) regulates the cardiac sympathetic afferent reflex (CSAR) contributing to sympathoexcitation in obese rats induced by a high-fat diet (42% kcal as fat) for 12 weeks. CSAR was evaluated by monitoring the changes of renal sympathetic nerve activity (RSNA) and the mean arterial pressure (MAP) responses to the epicardial application of capsaicin (CAP) in anaesthetized rats. In obese rats with hypertension (OH group) or without hypertension (OB group), the levels of PVN O2−, angiotensinII (Ang II), Ang II type 1 receptor (AT1R), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were elevated, whereas neural NO synthase (nNOS) and NO were significantly reduced. Moreover, CSAR was markedly enhanced, which promoted the elevation of plasma norepinephrine levels. The enhanced CSAR was attenuated by PVN application of the superoxide scavenger polyethylene glycol-superoxide dismutase (PEG-SOD) and the NO donor sodium nitroprusside (SNP), and was strengthened by the superoxide dismutase inhibitor diethyldithiocarbamic acid (DETC) and the nNOS inhibitor N(ω)-propyl-l-arginine hydrochloride (PLA); conversely, there was a smaller CSAR response to PLA or SNP in rats that received a low-fat (12% kcal) diet. Furthermore, PVN pretreatment with the AT1R antagonist losartan or with PEG-SOD, but not SNP, abolished Ang II-induced CSAR enhancement. These findings suggest that obesity alters the PVN O2− and NO system that modulates CSAR and promotes sympathoexcitation.
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Affiliation(s)
- Qing-Bo Lu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
| | - Jing Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
| | - Ying Kang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
| | - Hai-Jian Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
| | - Hui-Shan Wang
- Department of Pediatrics, The Fourth Clinical Medical College of Nanjing Medical University, Nanjing 210029, China.
| | - Yuan Wang
- Department of Pediatrics, The Fourth Clinical Medical College of Nanjing Medical University, Nanjing 210029, China.
| | - Guo-Qing Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
| | - Ye-Bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
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Cai W, Zhang Z, Huang Y, Sun H, Qiu L. Vaccarin alleviates hypertension and nephropathy in renovascular hypertensive rats. Exp Ther Med 2017; 15:924-932. [PMID: 29399101 PMCID: PMC5772753 DOI: 10.3892/etm.2017.5442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/02/2017] [Indexed: 12/11/2022] Open
Abstract
The kidney is an important organ in the regulation of blood pressure, and it is also one of the primary target organs of hypertension. Kidney damage in response to hypertension eventually leads to renal insufficiency. The authors previously demonstrated that vaccarin exhibits a protective role in endothelial injury. However, the effects of vaccarin on the two-kidney, one clip (2K1C) renovascular hypertension model and subsequent kidney injury have yet to be fully elucidated. The present study was designed to investigate the roles and mechanisms of vaccarin in attenuating hypertension and whether vaccarin had beneficial effects on kidney injury. The 2K1C rats had greater fibrosis, apoptosis, reactive oxygen species production, inflammation, angiotensin II (Ang II) and angiotensin type 1 (AT1) receptors in the right kidney compared with normotensive rats, which were alleviated by a high dose of vaccarin and captopril. Vaccarin treatment attenuated hypertension, reduced fibrosis markers, NADPH oxidase (NOX)-2, NOX-4, 3-nitrotyrosine, tumor necrosis factor-α, interleukin 1β (IL-1β), and IL-6 protein levels and altered pro-apoptotic protein levels including caspase-3, anti-apoptosis protein B cell lymphoma (Bcl)-2 and Bcl-2 associated X, apoptosis regulator in the right kidney of 2K1C rats. These findings suggest that the protective effects of vaccarin on the right kidney in renovascular hypertension are possibly due to downregulation of fibrosis, inflammatory molecules, oxidative stress, Ang II, and AT1 receptor levels.
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Affiliation(s)
- Weiwei Cai
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Zhenpeng Zhang
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Yiqi Huang
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Haijian Sun
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Liying Qiu
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
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Hypothalamic and inflammatory basis of hypertension. Clin Sci (Lond) 2017; 131:211-223. [PMID: 28057892 DOI: 10.1042/cs20160001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 11/07/2016] [Accepted: 11/21/2016] [Indexed: 02/07/2023]
Abstract
Hypertension is a major health problem with great consequences for public health. Despite its role as the primary cause of significant morbidity and mortality associated with cardiovascular disease, the pathogenesis of essential hypertension remains largely unknown. The central nervous system (CNS) in general, and the hypothalamus in particular, are intricately involved in the development and maintenance of hypertension. Over the last several decades, the understanding of the brain's role in the development of hypertension has dramatically increased. This brief review is to summarize the neural mechanisms of hypertension with a focus on neuroendocrine and neurotransmitter involvement, highlighting recent findings that suggest that hypothalamic inflammation disrupts key signalling pathways to affect the central control of blood pressure, and therefore suggesting future development of interventional strategies that exploit recent findings pertaining to the hypothalamic control of blood pressure as well as the inflammatory-sympathetic mechanisms involved in hypertension.
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Zhang SY, Xu MJ, Wang X. Adrenomedullin 2/intermedin: a putative drug candidate for treatment of cardiometabolic diseases. Br J Pharmacol 2017; 175:1230-1240. [PMID: 28407200 DOI: 10.1111/bph.13814] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/15/2017] [Accepted: 03/30/2017] [Indexed: 11/28/2022] Open
Abstract
Adrenomedullin (ADM) 2/intermedin (IMD) is a short peptide that belongs to the CGRP superfamily. Although it shares receptors with CGRP, ADM and amylin, ADM2 has significant and unique functions in the cardiovascular system. In the past decade, the cardiovascular effect of ADM2 has been carefully analysed. In this review, progress in understanding the effects of ADM2 on the cardiovascular system and its protective role in cardiometabolic diseases are summarized. LINKED ARTICLES This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.
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Affiliation(s)
- Song-Yang Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, 100191, China
| | - Ming-Jiang Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, 100191, China
| | - Xian Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, 100191, China
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Klimentova J, Cebova M, Barta A, Matuskova Z, Vrankova S, Rehakova R, Kovacsova M, Pechanova O. Effect of melatonin on blood pressure and nitric oxide generation in rats with metabolic syndrome. Physiol Res 2017; 65:S373-S380. [PMID: 27775422 DOI: 10.33549/physiolres.933436] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Melatonin, a multitasking indolamine, seems to be involved in a variety of physiological and metabolic processes via both receptor-mediated and receptor-independent mechanisms. The aim of our study was to find out whether melatonin can affect blood pressure (BP), nitric oxide synthase (NOS) activity, eNOS and nNOS protein expressions in rats with metabolic syndrome (SHR/cp). Rats were divided into four groups: 6-week-old male WKY andSHR/cp and age-matched WKY and SHR/cp treated with melatonin (10 mg/kg/day) for 3 weeks. BP was measured by tail-cuff plethysmography. NOS activity, eNOS and nNOS protein expressions were determined in the heart, aorta, brain cortex and cerebellum. MT(1) receptors were analyzed in the brain cortex and cerebellum. In SHR/cp rats, BP was decreased after melatonin treatment. In the same group, melatonin did not affect NOS activity and eNOS protein expression in the heart and aorta, while it increased both parameters in the brain cortex and cerebellum. Interestingly, melatonin elevated MT1 protein expression in the cerebellum. Neuronal NOS protein expression was not changed within the groups. In conclusion, increased NOS activity/eNOS upregulation in particular brain regions may contribute partially to BP decrease in SHR/cp rats after melatonin treatment. Participation of MT(1) receptors in this melatonin action may be supposed.
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Affiliation(s)
- J Klimentova
- Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Puzserova A, Bernatova I. Blood pressure regulation in stress: focus on nitric oxide-dependent mechanisms. Physiol Res 2017; 65:S309-S342. [PMID: 27775419 DOI: 10.33549/physiolres.933442] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Stress is considered a risk factor associated with the development of various civilization diseases including cardiovascular diseases, malignant tumors and mental disorders. Research investigating mechanisms involved in stress-induced hypertension have attracted much attention of physicians and researchers, however, there are still ambiguous results concerning a causal relationship between stress and long-term elevation of blood pressure (BP). Several studies have observed that mechanisms involved in the development of stress-induced hypertension include increased activity of sympathetic nervous system (SNS), glucocorticoid (GC) overload and altered endothelial function including decreased nitric oxide (NO) bioavailability. Nitric oxide is well known neurotransmitter, neuromodulator and vasodilator involved in regulation of neuroendocrine mechanisms and cardiovascular responses to stressors. Thus NO plays a crucial role in the regulation of the stress systems and thereby in the BP regulation in stress. Elevated NO synthesis, especially in the initial phase of stress, may be considered a stress-limiting mechanism, facilitating the recovery from stress to the resting levels via attenuation of both GC release and SNS activity as well as by increased NO-dependent vasorelaxation. On the other hand, reduced levels of NO were observed in the later phases of stress and in subjects with genetic predisposition to hypertension, irrespectively, in which reduced NO bioavailability may account for disruption of NO-mediated BP regulatory mechanisms and accentuated SNS and GC effects. This review summarizes current knowledge on the role of stress in development of hypertension with a special focus on the interactions among NO and other biological systems affecting blood pressure and vascular function.
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Affiliation(s)
- A Puzserova
- Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Dai X, Huang S, He Z, Wu F, Ding R, Chen Y, Liang C, Wu Z. Dysfunction of the thymus in mice with hypertension. Exp Ther Med 2017; 13:1386-1392. [PMID: 28413482 PMCID: PMC5377285 DOI: 10.3892/etm.2017.4125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/04/2016] [Indexed: 01/14/2023] Open
Abstract
The aim of this study was to evaluate thymus function in mice with hypertension. A total of 60 C57BL/6J mice were randomized into control, sham surgery and two-kidney, one-clip groups (n=20 in each). At 4 or 8 weeks after surgery, mice were sacrificed, and blood, spleens, kidneys and thymuses were harvested. The results of reverse transcription-quantitative polymerase chain reaction analysis revealed that the mRNA levels of Forkhead box protein N1 (Foxn1) and autoimmune regulator (AIRE) in the thymus tissue of mice from the HTN group were significantly lower than those from the control group at 4 and 8 weeks (P<0.05). Foxn1 and AIRE expression was also reduced in the sham surgery group at 4 weeks after surgery, but had recovered 4 weeks later. Similar results were observed for the expression of signal-joint T cell receptor excision circles and the percentages of T cell subsets. The present study indicates that impaired thymus function is associated with hypertension in mice, which suggests that thymus function may be a novel target for the treatment of patients with hypertension.
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Affiliation(s)
- Xianliang Dai
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Shuaibo Huang
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Zhiqing He
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Feng Wu
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Ru Ding
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Yihong Chen
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Chun Liang
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
| | - Zonggui Wu
- Department of Cardiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China
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Yang SX, Chen YX, Xu J, Yang ZH. Plasma Intermedin Level Indicates Severity and Treatment Efficacy of Septic Shock in Sprague-Dawley (SD) Rats. Med Sci Monit 2016; 22:5028-5034. [PMID: 27999422 PMCID: PMC5198747 DOI: 10.12659/msm.897885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The aim of this study was to investigate the value of plasma intermedin (IMD) in assessing severity and treatment efficacy of septic shock. MATERIAL AND METHODS Healthy male Sprague-Dawley (SD) rats were chosen and divided into a normal control group (n=15) and a shock model group (n=27) that received intravenous injection of lipopolysaccharide (LPS). Then, 3 specimens were taken from each group. The shock model group rats were divided into an LPS group and a treatment group with 12 rats each. The treatment group received intravenous injection of compound sodium lactate solution. Plasma IMD and IMD1-47 mRNA expressions were compared and analyzed. RESULTS Mean arterial pressure (MAP) was lower while white blood cell count and TNF-α were higher in the shock model group than in the normal control group (P<0.05). After 10 h and 20 h, the treatment group had lower plasma IMD and IMD1-47 mRNA expressions compared with the LPS group (P<0.05). Plasma IMD and IMD1-47 mRNA expressions in the LPS group after 20 h were significantly higher than after 10 h (P<0.05). IMD was positively correlated with interleukins (IL-3, IL-6, and IL-8), white blood cell count, and body temperature (all P<0.05), but were negatively correlated with systolic pressure (r=-0.8474, P=0.0040). CONCLUSIONS Plasma IMD level can effectively reflect the severity of septic shock and can be used as an important indicator of septic shock treatment effectiveness.
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Affiliation(s)
- Su-Xian Yang
- Department of Infectious Diseases, Linyi People's Hospital, Linyi, Shandong, China (mainland)
| | - Yun-Xiu Chen
- Department of Infectious Diseases, Linyi People's Hospital, Linyi, Shandong, China (mainland)
| | - Jing Xu
- Department of Infectious Diseases, Linyi People's Hospital, Linyi, Shandong, China (mainland)
| | - Zhao-Hui Yang
- Department of Infectious Diseases, Linyi People's Hospital, Linyi, Shandong, China (mainland)
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Nishihara M, Takesue K, Hirooka Y. Renal denervation enhances GABA-ergic input into the PVN leading to blood pressure lowering in chronic kidney disease. Auton Neurosci 2016; 204:88-97. [PMID: 27729205 DOI: 10.1016/j.autneu.2016.09.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/30/2016] [Accepted: 09/30/2016] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Sympathoexcitation plays an important role in the pathogenesis of hypertension in patients with chronic kidney disease (CKD). The paraventricular nucleus of the hypothalamus (PVN) in the brain controls sympathetic outflow through γ-amino butyric acid (GABA)-ergic mechanisms. Renal denervation (RDN) exerts a long-term antihypertensive effect in hypertension with CKD; however, the effects of RDN on sympathetic nerve activity and GABA-ergic modulation in the PVN are not clear. We aimed to elucidate whether RDN modulates sympathetic outflow through GABA-ergic mechanisms in the PVN in hypertensive mice with CKD. METHODS AND RESULTS In 5/6-nephrectomized male Institute of Cancer Research mice (Nx) at 4 weeks after nephrectomy, systolic blood pressure (SBP) was significantly increased, accompanied by sympathoexcitation. The Nx-mice underwent RDN or sham operation, and the mice were divided into three groups (Control, Nx-Sham, and Nx-RDN). At 2 weeks after RDN, SBP was significantly decreased and urinary sodium excretion was increased in Nx-RDN compared with Nx-Sham. Urinary norepinephrine excretion (uNE) levels did not differ significantly between Nx-RDN and Nx-Sham. At 6 weeks after RDN, SBP continued to decrease and uNE levels also decreased in Nx-RDN compared with Nx-Sham. Bicuculline microinjection into the PVN increased mean arterial pressure and lumbar sympathetic nerve activity in all groups. The pressor responses and change in lumbar sympathetic nerve activity were significantly attenuated in Nx-Sham, but were enhanced in Nx-RDN at 6 weeks after RDN. CONCLUSIONS The findings from the present study indicate that RDN has a prolonged antihypertensive effect and, at least in the late phase, decreases sympathetic nerve activity in association with enhanced GABA-ergic input into the PVN in mice with CKD.
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Affiliation(s)
- Masaaki Nishihara
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Ko Takesue
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Yoshitaka Hirooka
- Department of Advanced Cardiovascular Regulation and Therapeutics for Cardiovascular Diseases, Kyushu University Center for Disruptive Cardiovascular Medicine, Fukuoka, Japan.
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Sun HJ, Chen D, Han Y, Zhou YB, Wang JJ, Chen Q, Li YH, Gao XY, Kang YM, Zhu GQ. Relaxin in paraventricular nucleus contributes to sympathetic overdrive and hypertension via PI3K-Akt pathway. Neuropharmacology 2016; 103:247-56. [DOI: 10.1016/j.neuropharm.2015.12.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 11/29/2015] [Accepted: 12/28/2015] [Indexed: 12/01/2022]
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Abstract
The etiology of hypertension, a critical public health issue affecting one in three US adults, involves the integration of the actions of multiple organ systems, including the central nervous system. Increased activation of the central nervous system, driving enhanced sympathetic outflow and increased blood pressure, has emerged as a major contributor to the pathogenesis of hypertension. The hypothalamus is a key brain site acting to integrate central and peripheral inputs to ultimately impact blood pressure in multiple disease states that evoke hypertension. This review highlights recent advances that have identified novel signal transduction mechanisms within multiple hypothalamic nuclei (e.g., paraventricular nucleus, arcuate nucleus) acting to drive the pathophysiology of hypertension in neurogenic hypertension, angiotensin II hypertension, salt-sensitive hypertension, chronic intermittent hypoxia, and obesity-induced hypertension. Increased understanding of hypothalamic activity in hypertension has the potential to identify novel targets for future therapeutic interventions designed to treat hypertension.
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Neuronal and Endothelial Nitric Oxide Synthases in the Paraventricular Nucleus Modulate Sympathetic Overdrive in Insulin-Resistant Rats. PLoS One 2015; 10:e0140762. [PMID: 26485682 PMCID: PMC4613827 DOI: 10.1371/journal.pone.0140762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 09/30/2015] [Indexed: 11/19/2022] Open
Abstract
A central mechanism participates in sympathetic overdrive during insulin resistance (IR). Nitric oxide synthase (NOS) and nitric oxide (NO) modulate sympathetic nerve activity (SNA) in the paraventricular nucleus (PVN), which influences the autonomic regulation of cardiovascular responses. The aim of this study was to explore whether the NO system in the PVN is involved in the modulation of SNA in fructose-induced IR rats. Control rats received ordinary drinking water, whereas IR rats received 12.5% fructose-containing drinking water for 12 wks to induce IR. Basal SNA was assessed based on the changes in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) in response to chemicals administered to the PVN. We found an increased plasma norepinephrine level but significantly reduced NO content and neuronal NOS (nNOS) and endothelial NOS (eNOS) protein expression levels in the PVN of IR rats compared to Control rats. No difference in inducible NOS (iNOS) protein expression was observed between the two groups. In anesthetized rats, the microinjection of sodium nitroprusside (SNP), an NO donor, or Nω-nitro-L-arginine methyl ester (L-NAME), a non-selective inhibitor of NOS, into the PVN significantly decreased and increased basal SNA, respectively, in both normal and IR rats, but these responses to SNP and L-NAME in IR rats were smaller than those in normal rats. The administration of selective inhibitors of nNOS or eNOS, but not iNOS, to the PVN significantly increased basal SNA in both groups, but these responses were also smaller in IR rats. Moreover, IR rats exhibited reduced nNOS and eNOS activity in the PVN. In conclusion, these data indicate that the decreased protein expression and activity levels of nNOS and eNOS in the PVN lead to a reduction in the NO content in the PVN, thereby contributing to a subsequent enhancement in sympathoexcitation during IR.
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Chen WW, Xiong XQ, Chen Q, Li YH, Kang YM, Zhu GQ. Cardiac sympathetic afferent reflex and its implications for sympathetic activation in chronic heart failure and hypertension. Acta Physiol (Oxf) 2015; 213:778-94. [PMID: 25598170 DOI: 10.1111/apha.12447] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 10/22/2014] [Accepted: 12/23/2014] [Indexed: 12/21/2022]
Abstract
Persistent excessive sympathetic activation greatly contributes to the pathogenesis of chronic heart failure (CHF) and hypertension. Cardiac sympathetic afferent reflex (CSAR) is a sympathoexcitatory reflex with positive feedback characteristics. Humoral factors such as bradykinin, adenosine and reactive oxygen species produced in myocardium due to myocardial ischaemia stimulate cardiac sympathetic afferents and thereby reflexly increase sympathetic activity and blood pressure. The CSAR is enhanced in myocardial ischaemia, CHF and hypertension. The enhanced CSAR at least partially contributes to the sympathetic activation and pathogenesis of these diseases. Nucleus of the solitary tract (NTS), hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla are the most important central sites involved in the modulation and integration of the CSAR. Angiotensin II, AT1 receptors and NAD(P)H oxidase-derived superoxide anions pathway in the PVN are mainly responsible for the enhanced CSAR in CHF and hypertension. Central angiotensin-(1-7), nitric oxide, endothelin, intermedin, hydrogen peroxide and several other signal molecules are involved in regulating CSAR. Blockade of the CSAR shows beneficial effects in CHF and hypertension. This review focuses on the anatomical and physiological basis of the CSAR, the interaction of CSAR with baroreflex and chemoreflex, and the role of enhanced CSAR in the pathogenesis of CHF and hypertension.
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Affiliation(s)
- W.-W. Chen
- Department of Physiology; Key Laboratory of Cardiovascular Disease and Molecular Intervention; Nanjing Medical University; Nanjing Jiangsu China
| | - X.-Q. Xiong
- Department of Physiology; Key Laboratory of Cardiovascular Disease and Molecular Intervention; Nanjing Medical University; Nanjing Jiangsu China
| | - Q. Chen
- Department of Pathophysiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-H. Li
- Department of Pathophysiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-M. Kang
- Department of Physiology and Pathophysiology; Cardiovascular Research Center; Xi'an Jiaotong University School of Medicine; Xi'an China
| | - G.-Q. Zhu
- Department of Physiology; Key Laboratory of Cardiovascular Disease and Molecular Intervention; Nanjing Medical University; Nanjing Jiangsu China
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Ye BH, Lee SJ, Choi YW, Park SY, Kim CD. Preventive effect of gomisin J from Schisandra chinensis on angiotensin II-induced hypertension via an increased nitric oxide bioavailability. Hypertens Res 2014; 38:169-77. [DOI: 10.1038/hr.2014.162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 09/04/2014] [Accepted: 10/23/2014] [Indexed: 01/18/2023]
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Zhang F, Sun HJ, Xiong XQ, Chen Q, Li YH, Kang YM, Wang JJ, Gao XY, Zhu GQ. Apelin-13 and APJ in paraventricular nucleus contribute to hypertension via sympathetic activation and vasopressin release in spontaneously hypertensive rats. Acta Physiol (Oxf) 2014; 212:17-27. [PMID: 24995933 DOI: 10.1111/apha.12342] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 04/23/2014] [Accepted: 07/01/2014] [Indexed: 12/13/2022]
Abstract
AIMS Apelin is a specific endogenous ligand of orphan G protein-coupled receptor APJ. This study was designed to determine the roles and mechanisms of apelin-13 and APJ in paraventricular nucleus (PVN) in renal sympathetic nerve activity (RSNA), arginine vasopressin (AVP) release and mean arterial pressure (MAP) in spontaneously hypertensive rats (SHR). METHOD Acute experiment was carried out in 13-week-old male SHR and Wistar-Kyoto rats (WKY) under anaesthesia. RSNA and MAP responses to the PVN microinjection were determined. Apelin and APJ expressions were examined with quantitative real-time PCR and Western blot. AVP and noradrenaline were determined with ELISA. Osmotic minipumps were used for chronic PVN infusion in conscious WKY. RESULTS Apelin and APJ in the PVN were up-regulated in SHR. The PVN microinjection of apelin-13 increased, but APJ antagonist F13A decreased the RSNA, MAP, plasma noradrenaline and AVP levels in SHR. N-methyl-D-aspartate receptor (NMDAR) antagonist plus non-NMDAR antagonist abolished the apelin-13-induced sympathetic activation rather than AVP release. NMDAR antagonist or non-NMDAR antagonist alone attenuated the apelin-13-induced sympathetic activation. Chronic infusion of apelin-13 into the PVN in normotensive rats induced hypertension, increased plasma noradrenaline and AVP levels and promoted myocardial atrial natriuretic peptide and beta-myosin heavy chain mRNA expressions, two indicative markers of cardiac hypertrophy. CONCLUSION Apelin-13 and APJ in the PVN contribute to hypertension via sympathetic activation and AVP release in SHR. The sympatho-excitatory effect of apeline-13 is mediated by both NMDAR and non-NMDAR in the PVN. Persistent activation of APJ in the PVN induces hypertension.
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Affiliation(s)
- F. Zhang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - H.-J. Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - X.-Q. Xiong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Q. Chen
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-H. Li
- Department of Pathophysiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-M. Kang
- Department of Physiology and Pathophysiology; Cardiovascular Research Center; Xi'an Jiaotong University School of Medicine; Xi'an China
| | - J.-J. Wang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - X.-Y. Gao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - G.-Q. Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
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Ni X, Zhang J, Tang C, Qi Y. Intermedin/adrenomedullin2: an autocrine/paracrine factor in vascular homeostasis and disease. SCIENCE CHINA-LIFE SCIENCES 2014; 57:781-9. [DOI: 10.1007/s11427-014-4701-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/20/2014] [Indexed: 12/01/2022]
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Zhou H, Sun HJ, Chang JR, Ding L, Gao Q, Tang CS, Zhu GQ, Zhou YB. Cardiac sympathetic afferent reflex response to intermedin microinjection into paraventricular nucleus is mediated by nitric oxide and γ-amino butyric acid in hypertensive rats. Exp Biol Med (Maywood) 2014; 239:1352-9. [DOI: 10.1177/1535370214533882] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Intermedin (IMD) is a member of calcitonin/calcitonin gene-related peptide (CGRP) and involves in the regulation of cardiovascular function in both peripheral tissues and central nervous system (CNS). Paraventricular nucleus (PVN) of hypothalamus is an important site in the control of cardiac sympathetic afferent reflex (CSAR) which participates in sympathetic over-excitation of hypertension. The aim of this study is to investigate whether IMD in the PVN is involved in the inhibition of CSAR and its related mechanism in hypertension. Rats were subjected to two-kidney one-clip (2K1C) surgery to induce renovascular hypertension or sham-operation (Sham). Acute experiments were carried out four weeks later under anesthesia. The CSAR was evaluated with the renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) responses to the epicardial application of capsaicin. The RSNA and MAP were recorded in sinoaortic-denervated, cervical-vagotomized and anesthetized rats. Bilateral PVN microinjection of IMD (25 pmol) caused greater decrease in the CSAR in 2K1C rats than in Sham rats, which was prevented by pretreatment with adrenomedullin (AM) receptor antagonist AM22-52, non-selective nitric oxide (NO) synthase (NOS) inhibitor l-NAME or γ-amino butyric acid (GABA)B receptor blocker CGP-35348. PVN pretreatment with CGRP receptor antagonist CGRP8-37 or GABAA receptor blocker gabazine had no significant effect on the CSAR response to IMD. AM22-52, l-NAME and CGP-35348 in the PVN could increase CSAR in Sham and 2K1C rats. These data indicate that IMD in the PVN inhibits CSAR via AM receptor, and both NO and GABA in the PVN involve in the effect of IMD on CSAR in Sham and renovascular hypertensive rats.
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Affiliation(s)
- Hong Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
- Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing 210029, China
| | - Hai-jian Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
| | - Jin-rui Chang
- Department of Physiology, Xi'an Medical University, Shanxi 710021, China
| | - Lei Ding
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
| | - Qing Gao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
- Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing 210029, China
| | - Chao-shu Tang
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Guo-qing Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
| | - Ye-bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029, China
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Gan XB, Sun HJ, Chen D, Zhang LL, Zhou H, Chen LY, Zhou YB. Intermedin in the paraventricular nucleus attenuates cardiac sympathetic afferent reflex in chronic heart failure rats. PLoS One 2014; 9:e94234. [PMID: 24709972 PMCID: PMC3978024 DOI: 10.1371/journal.pone.0094234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 03/13/2014] [Indexed: 01/06/2023] Open
Abstract
Background and Aim Intermedin (IMD) is a member of calcitonin/calcitonin gene-related peptide (CGRP) family together with adrenomedullin (AM) and amylin. It has a wide distribution in the central nervous system (CNS) especially in hypothalamic paraventricular nucleus (PVN). Cardiac sympathetic afferent reflex (CSAR) is enhanced in chronic heart failure (CHF) rats. The aim of this study is to determine the effect of IMD in the PVN on CSAR and its related mechanisms in CHF rats. Methodology/Principal Findings Rats were subjected to left descending coronary artery ligation to induce CHF or sham-operation (Sham). Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) were recorded. CSAR was evaluated by the RSNA and MAP responses to epicardial application of capsaicin. Acute experiments were carried out 8 weeks after coronary ligation or sham surgery under anesthesia. IMD and angiotensin II (Ang II) levels in the PVN were up-regulated in CHF rats. Bilateral PVN microinjection of IMD caused greater decreases in CSAR and the baseline RSNA and MAP in CHF rats than those in Sham rats. The decrease of CSAR caused by IMD was prevented by pretreatment with AM receptor antagonist AM22-52, but not CGRP receptor antagonist CGRP8-37. Ang II in the PVN significantly enhanced CSAR and superoxide anions level, which was inhibited by PVN pretreatment with IMD or tempol (a superoxide anions scavenger) in Sham and CHF rats. Conclusion IMD in the PVN inhibits CSAR via AM receptor, and attenuates the effects of Ang II on CSAR and superoxide anions level in CHF rats. PVN superoxide anions involve in the effect of IMD on attenuating Ang II-induced CSAR response.
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Affiliation(s)
- Xian-Bing Gan
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, China; Department of Physiology, Anhui University of Chinese Medicine, Hefei, China
| | - Hai-Jian Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Dan Chen
- Department of Physiology, Anhui University of Chinese Medicine, Hefei, China
| | - Ling-Li Zhang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Hong Zhou
- Laboratory Center for Basic Medical Sciences, Department of Medical Physiology and Biochemistry, Nanjing Medical University, Nanjing, China
| | - Li-Yan Chen
- Department of Haematology, the 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ye-Bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, China
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