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Lu Y, Wang YD, Xu TQ, Zhao XH, Zhou J, Jin LH, Liu JJ. Pyridostigmine attenuates hypertension by inhibiting activation of the renin-angiotensin system in the hypothalamic paraventricular nucleus. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03156-x. [PMID: 38767671 DOI: 10.1007/s00210-024-03156-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/10/2024] [Indexed: 05/22/2024]
Abstract
Activation of the renin-angiotensin system (RAS) triggers oxidative stress and an inflammatory response in the hypothalamic paraventricular nucleus (PVN), in turn increasing the sympathetic hyperactivity that is a major cause of hypertension. Pyridostigmine has cardioprotective effects by suppressing the RAS of myocardial tissue. However, whether pyridostigmine attenuates hypertension by inhibiting the RAS of the PVN remains unclear. We thus investigated the effect and mechanism of pyridostigmine on two-kidney one-clip (2K1C)-induced hypertension. 2K1C rats received pyridostigmine, or not, for 8 weeks. Cardiovascular function, hemodynamic parameters, and autonomic activity were measured. The PVN levels of pro-/anti-inflammatory cytokines, oxidative stress, and RAS signaling molecules were evaluated. Our results showed that hypertension was accompanied by cardiovascular dysfunction and an autonomic imbalance characterized by enhanced sympathetic but diminished vagal activity. The PVN levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS), NOX-2, and malondialdehyde (MDA) increased; those of IL-10 and superoxide dismutase (SOD) decreased. Moreover, the RAS signaling pathway was activated, as evidenced by increased levels of the angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and the Ang II type 1 receptor (AT1R) and a decreased AT2R level. Pyridostigmine lowered blood pressure and improved cardiovascular function, associated with restoration of the autonomic balance. Meanwhile, pyridostigmine decreased PVN IL-6, TNF-α, ROS, NOX-2, and MDA levels and increased IL-10 and SOD levels. Additionally, pyridostigmine suppressed PVN ACE, Ang II, and AT1R levels and increased AT2R expression. Pyridostigmine attenuated hypertension by inhibiting PVN oxidative stress and inflammation induced by the RAS.
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Affiliation(s)
- Yi Lu
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
- Department of Pharmacy, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Yi-Dong Wang
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Tian-Qi Xu
- Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University School of Basic Medical Sciences, Xi'an, China
| | - Xu-He Zhao
- Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University School of Basic Medical Sciences, Xi'an, China
| | - Jun Zhou
- Department of Pharmacology, Xi'an Jiaotong University School of Basic Medical Sciences, Xi'an, China
| | - Lian-Hai Jin
- Low Pressure and Low Oxygen Environment and Health Intervention Innovation Center, Jilin Medical University, Jilin, China
| | - Jin-Jun Liu
- Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University School of Basic Medical Sciences, Xi'an, China.
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Hong N, Kim KJ, Yu MH, Jeong SH, Lee S, Lim JS, Rhee Y. Risk of dementia in primary aldosteronism compared with essential hypertension: a nationwide cohort study. Alzheimers Res Ther 2023; 15:136. [PMID: 37568223 PMCID: PMC10416485 DOI: 10.1186/s13195-023-01274-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/12/2023] [Indexed: 08/13/2023]
Abstract
BACKGROUND Although hypertension is a critical risk factor for dementia, the association between primary aldosteronism (PA) and dementia has been scarcely reported. We aimed to investigate whether the risk of dementia in patients with PA was elevated compared with patients with essential hypertension (EH). METHODS From the National Health Insurance Claim database in Korea (2003-2017), 3,687 patients with PA (adrenalectomy [ADX], n = 1,339, mineralocorticoid receptor antagonist [MRA] n = 2,348) with no prior dementia were age- and sex-matched at a 1:4 ratio to patients with EH (n = 14,741). The primary outcomes were all-cause dementia events, including Alzheimer's disease, vascular dementia, or other dementia combined with a prescription of one or more medications for dementia (donepezil, galantamine, memantine, or rivastigmine). Multivariable Cox regression models were used to evaluate the hazard ratios (HRs) and 95% confidence intervals for the outcome incidence rates between patients with PA and their EH matches. RESULTS During a median follow-up of 5.2 years, there were 156 cases of all-cause dementia (4.2%), 140 cases of Alzheimer's disease (3.8%), and 65 cases of vascular dementia (1.8%). Compared with EH, the risk of all-cause dementia was increased in treated PA (unadjusted hazard ratio [HR] 1.26; p < 0.011). Among PA, MRA group had higher risks of all-cause dementia, especially vascular dementia, adjusted for age, sex, income, comorbidities, and concurrent medication (adjusted HR 1.31; p = 0.027 and adjusted HR 1.62; p = 0.020, respectively) compared to EH. ADX group seemed to have a lower dementia risk than the EH group, but there was no statistical significance after full adjustment. This trend became more prominent when the dementia risks were evaluated from the time of hypertension diagnosis rather than treatment initiation for PA. CONCLUSION The findings of this cohort study suggest that PA, especially the MRA group, is associated with an increased risk of dementia. Monitoring cognitive function in PA patients even after treatment initiation might be warranted to prevent dementia.
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Affiliation(s)
- Namki Hong
- Department of Internal Medicine, Severance Hospital, Endocrine Research Institute, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea
| | - Kyoung Jin Kim
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
| | - Min Heui Yu
- SENTINEL Team, Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seong Ho Jeong
- Department of Neurology, Inje University Sanggye Paik Hospital, Seoul, Republic of Korea
| | - Seunghyun Lee
- Department of Internal Medicine, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, 20, Ilsan-Ro, Wonju-Si, Gangwon-Do, 26426, Republic of Korea
| | - Jung Soo Lim
- Department of Internal Medicine, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, 20, Ilsan-Ro, Wonju-Si, Gangwon-Do, 26426, Republic of Korea.
| | - Yumie Rhee
- Department of Internal Medicine, Severance Hospital, Endocrine Research Institute, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.
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Oliveira V, Reho JJ, Balapattabi K, Ritter ML, Mathieu NM, Opichka MA, Lu KT, Grobe CC, Silva SD, Wackman KK, Nakagawa P, Segar JL, Sigmund CD, Grobe JL. Chronic intracerebroventricular infusion of angiotensin II causes dose- and sex-dependent effects on intake behaviors and energy homeostasis in C57BL/6J mice. Am J Physiol Regul Integr Comp Physiol 2022; 323:R410-R421. [PMID: 35816717 PMCID: PMC9512112 DOI: 10.1152/ajpregu.00091.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/15/2022] [Accepted: 07/09/2022] [Indexed: 11/22/2022]
Abstract
The renin-angiotensin system (RAS) within the brain is implicated in the control of fluid and electrolyte balance, autonomic functions, blood pressure, and energy expenditure. Mouse models are increasingly used to explore these mechanisms; however, sex and dose dependencies of effects elicited by chronic intracerebroventricular (ICV) angiotensin II (ANG II) infusion have not been carefully established in this species. To examine the interactions among sex, body mass, and ICV ANG II on ingestive behaviors and energy balance, young adult C57BL/6J mice of both sexes were studied in a multiplexed metabolic phenotyping system (Promethion) during chronic infusion of ANG II (0, 5, 20, or 50 ng/h). At these infusion rates, ANG II caused accelerating dose-dependent increases in drinking and total energy expenditure in male mice, but female mice exhibited a complex biphasic response with maximum responses at 5 ng/h. Body mass differences did not account for sex-dependent differences in drinking behavior or total energy expenditure. In contrast, resting metabolic rate was similarly increased by ICV ANG II in a dose-dependent manner in both sexes after correction for body mass. We conclude that chronic ICV ANG II stimulates water intake, resting, and total energy expenditure in male C57BL/6J mice following straightforward accelerating dose-dependent kinetics, but female C57BL/6J mice exhibit complex biphasic responses to ICV ANG II. Furthermore, control of resting metabolic rate by ANG II is dissociable from mechanisms controlling fluid intake and total energy expenditure. Future studies of the sex dependency of ANG II within the brain of mice must be designed to carefully consider the biphasic responses that occur in females.
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Affiliation(s)
- Vanessa Oliveira
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - John J Reho
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin
| | | | - McKenzie L Ritter
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Natalia M Mathieu
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Megan A Opichka
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ko-Ting Lu
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Connie C Grobe
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Sebastião D Silva
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Kelsey K Wackman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Pablo Nakagawa
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jeffrey L Segar
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Curt D Sigmund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Justin L Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin
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4
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Neuroprotection in Stroke-Focus on the Renin-Angiotensin System: A Systematic Review. Int J Mol Sci 2022; 23:ijms23073876. [PMID: 35409237 PMCID: PMC8998496 DOI: 10.3390/ijms23073876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 01/01/2023] Open
Abstract
Stroke is the primary cause of disability in the adult population. Hypertension represents the leading risk factor being present in almost half the patients. The renin-angiotensin system is involved in the physiopathology of stroke and has an essential impact on hypertension as a risk factor. This article targeted the role of the renin-angiotensin system in stroke neuroprotection by reviewing the current literature available. The mechanism of action of the renin-angiotensin system was observed through the effects on AT1, AT2, and Mas receptors. The neuroprotective properties ascertained by angiotensin in stroke seem to be independent of the blood pressure reduction mechanism, and include neuroregeneration, angiogenesis, and increased neuronal resistance to hypoxia. The future relationship of stroke and the renin-angiotensin system is full of possibilities, as new agonist molecules emerge as potential candidates to restrict the impairment caused by stroke.
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Kamaleswaran R, Sadan O, Kandiah P, Li Q, Coopersmith CM, Buchman TG. Altered Heart Rate Variability Early in ICU Admission Differentiates Critically Ill Coronavirus Disease 2019 and All-Cause Sepsis Patients. Crit Care Explor 2021; 3:e0570. [PMID: 34984336 PMCID: PMC8718227 DOI: 10.1097/cce.0000000000000570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
IMPORTANCE Altered heart rate variability has been associated with autonomic dysfunction in a number of disease profiles, in this work we elucidate differences in the biomarker among patients with all-cause sepsis and coronavirus disease 2019. OBJECTIVES To measure heart rate variability metrics in critically ill coronavirus disease 2019 patients with comparison to all-cause critically ill sepsis patients. DESIGN SETTING AND PARTICIPANTS Retrospective analysis of coronavirus disease 2019 patients admitted to an ICU for at least 24 hours at any of Emory Healthcare ICUs between March 2020 and April 2020 up to 5 days of ICU stay. The comparison group was a cohort of all-cause sepsis patients prior to coronavirus disease 2019 pandemic. MAIN OUTCOMES AND MEASURES Continuous waveforms were captured from the patient monitor. The electrocardiogram was then analyzed for each patient over a 300 seconds observational window that was shifted by 30 seconds in each iteration from admission till discharge. A total of 23 heart rate variability metrics were extracted in each iteration. We use the Kruskal-Wallis and Steel-Dwass tests (p < 0.05) for statistical analysis and interpretations of heart rate variability multiple measures. RESULTS A total of 141 critically ill coronavirus disease 2019 patients met inclusion criteria, who were compared with 208 patients with all-cause sepsis. Three nonlinear markers, including the ratio of standard deviation derived from the Poincaré plot, sample entropy, and approximate entropy and four linear features, including mode of beat-to-beat interval, acceleration capacity, deceleration capacity, and the proportion of consecutive RR intervals that differ by more than 50 ms, were all statistically significant (p < 0.05) between the coronavirus disease 2019 and all-cause sepsis cohorts. The three nonlinear features and acceleration capacity, deceleration capacity, and beat-to-beat interval (mode) were statistically significant (p < 0.05) when comparing pairwise analysis among the combinations of survivors and nonsurvivors between the coronavirus disease 2019 and sepsis cohorts. Temporal analysis of the main markers showed low variability across the 5 days of analysis compared with sepsis patients. CONCLUSIONS AND RELEVANCE In this descriptive statistical study, heart rate variability measures were found to be statistically different across critically ill patients infected with severe acute respiratory syndrome coronavirus 2 and distinct from bacterial sepsis.
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Affiliation(s)
- Rishikesan Kamaleswaran
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA
- Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA
| | - Ofer Sadan
- Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA
- Department of Neurology and Neurosurgery, Division of Neurocritical Care, Emory University School of Medicine, Atlanta, GA
| | - Prem Kandiah
- Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA
- Department of Neurology and Neurosurgery, Division of Neurocritical Care, Emory University School of Medicine, Atlanta, GA
| | - Qiao Li
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA
| | - Craig M Coopersmith
- Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA
- Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Timothy G Buchman
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA
- Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA
- Department of Surgery, Emory University School of Medicine, Atlanta, GA
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6
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Zhao W, Zhao YL, Liu M, Liu L, Wang Y. Possible repair mechanisms of renin-angiotensin system inhibitors, matrix metalloproteinase-9 inhibitors and protein hormones on methamphetamine-induced neurotoxicity. Mol Biol Rep 2021; 48:7509-7516. [PMID: 34623593 DOI: 10.1007/s11033-021-06741-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 09/08/2021] [Indexed: 12/31/2022]
Abstract
Methamphetamine is a highly addictive central stimulant with extensive and strong neurotoxicity. The neurotoxicity of methamphetamine is closely related to the imbalance of dopamine levels and the destruction of the blood-brain barrier. An increase in dopamine may induce adverse effects such as behavioral sensitization and excessive locomotion. Damage to the blood-brain barrier can cause toxic or harmful substances to leak to the central nervous system, leading to neurotoxicity. The renin-angiotensin system is essential for the regulation of dopamine levels in the brain. Matrix metalloproteinase-9 causes reward effects and behavioral sensitization by inducing dopamine release. Prolactin has been shown to be involved in the regulation of tight junction proteins and the integrity of the blood-brain barrier. At present, the treatment of methamphetamine detoxification is still based on psychotherapy, and there is no specific medicine. With the rapid increase in global seizures of methamphetamine, the treatment of its toxicity has attracted more and more attention. This review intends to summarize the therapeutic mechanisms of renin-angiotensin inhibitors, matrix metalloproteinase-9 inhibitors and protein hormones (prolactin) on methamphetamine neurotoxicity. The repair effects of these three on methamphetamine may be related to the maintenance of brain dopamine balance and the integrity of the blood-brain barrier. This review is expected to provide the new therapeutic strategy of methamphetamine toxicity.
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Affiliation(s)
- Wei Zhao
- Department of Drug Control, Criminal Investigation Police University of China, Shenyang, 110854, Liaoning, People's Republic of China.,Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Yuan-Ling Zhao
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Ming Liu
- Department of Drug Control, Criminal Investigation Police University of China, Shenyang, 110854, Liaoning, People's Republic of China
| | - Lian Liu
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Yun Wang
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China.
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7
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Hasegawa Y, Uchikawa H, Kajiwara S, Morioka M. Central sympathetic nerve activation in subarachnoid hemorrhage. J Neurochem 2021; 160:34-50. [PMID: 34525222 DOI: 10.1111/jnc.15511] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/04/2021] [Accepted: 09/07/2021] [Indexed: 12/12/2022]
Abstract
Subarachnoid hemorrhage (SAH) is a life-threatening condition, and although its two main complications-cerebral vasospasm (CVS)/delayed cerebral ischemia (DCI) and early brain injury (EBI)-have been widely studied, prognosis has not improved over time. The sympathetic nerve (SN) system is important for the regulation of cardiovascular function and is closely associated with cerebral vessels and the regulation of cerebral blood flow and cerebrovascular function; thus, excessive SN activation leads to a rapid breakdown of homeostasis in the brain. In the hyperacute phase, patients with SAH can experience possibly lethal conditions that are thought to be associated with SN activation (catecholamine surge)-related arrhythmia, neurogenic pulmonary edema, and irreversible injury to the hypothalamus and brainstem. Although the role of the SN system in SAH has long been investigated and considerable evidence has been collected, the exact pathophysiology remains undetermined, mainly because the relationships between the SN system and SAH are complicated, and many SN-modulating factors are involved. Thus, research concerning these relationships needs to explore novel findings that correlate with the relevant concepts based on past reliable evidence. Here, we explore the role of the central SN (CSN) system in SAH pathophysiology and provide a comprehensive review of the functional CSN network; brain injury in hyperacute phase involving the CSN system; pathophysiological overlap between the CSN system and the two major SAH complications, CVS/DCI and EBI; CSN-modulating factors; and SAH-related extracerebral organ injury. Further studies are warranted to determine the specific roles of the CSN system in the brain injuries associated with SAH.
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Affiliation(s)
- Yu Hasegawa
- Department of Pharmaceutical Science, School of Pharmacy at Fukuoka, International University of Health and Welfare, Okawa, Fukuoka, Japan.,Department of Neurosurgery, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Hiroki Uchikawa
- Department of Neurosurgery, Kumamoto University School of Medicine, Kumamoto, Kumamoto, Japan
| | - Sosho Kajiwara
- Department of Neurosurgery, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Motohiro Morioka
- Department of Neurosurgery, Kurume University School of Medicine, Kurume, Fukuoka, Japan
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8
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Lucera GM, Menani JV, Colombari E, Colombari DSA. ANG II and Aldosterone Acting Centrally Participate in the Enhanced Sodium Intake in Water-Deprived Renovascular Hypertensive Rats. Front Pharmacol 2021; 12:679985. [PMID: 34113255 PMCID: PMC8186501 DOI: 10.3389/fphar.2021.679985] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/04/2021] [Indexed: 11/29/2022] Open
Abstract
Renovascular hypertension is a type of secondary hypertension caused by renal artery stenosis, leading to an increase in the renin–angiotensin–aldosterone system (RAAS). Two-kidney, 1-clip (2K1C) is a model of renovascular hypertension in which rats have an increased sodium intake induced by water deprivation (WD), a common situation found in the nature. In addition, a high-sodium diet in 2K1C rats induces glomerular lesion. Therefore, the purpose of this study was to investigate whether angiotensin II (ANG II) and/or aldosterone participates in the increased sodium intake in 2K1C rats under WD. In addition, we also verified if central AT1 and mineralocorticoid receptor blockade would change the high levels of arterial pressure in water-replete (WR) and WD 2K1C rats, because blood pressure changes can facilitate or inhibit water and sodium intake. Finally, possible central areas activated during WD or WD followed by partial rehydration (PR) in 2K1C rats were also investigated. Male Holtzman rats (150–180 g) received a silver clip around the left renal artery to induce renovascular hypertension. Six weeks after renal surgery, a stainless-steel cannula was implanted in the lateral ventricle, followed by 5–7 days of recovery before starting tests. Losartan (AT1 receptor antagonist) injected intracerebroventricularly attenuated water intake during the thirst test. Either icv losartan or RU28318 (mineralocorticoid receptor antagonist) reduced 0.3 M NaCl intake, whereas the combination of losartan and RU28318 icv totally blocked 0.3 M NaCl intake induced by WD in 2K1C rats. Losartan and RU28318 icv did not change hypertension levels of normohydrated 2K1C rats, but reduced the increase in mean arterial pressure (MAP) produced by WD. c-Fos expression increased in the lamina terminalis and in the NTS in WD condition, and increased even more after WD-PR. These results suggest the participation of ANG II and aldosterone acting centrally in the enhanced sodium intake in WD 2K1C rats, and not in the maintenance of hypertension in satiated and fluid-replete 2K1C rats.
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Affiliation(s)
- Gabriela Maria Lucera
- Department of Physiology and Pathology, School of Dentistry, Sao Paulo State University, Araraquara, Brazil
| | - José Vanderlei Menani
- Department of Physiology and Pathology, School of Dentistry, Sao Paulo State University, Araraquara, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, Sao Paulo State University, Araraquara, Brazil
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9
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Dupont AG, Légat L. GABA is a mediator of brain AT 1 and AT 2 receptor-mediated blood pressure responses. Hypertens Res 2020; 43:995-1005. [PMID: 32451494 DOI: 10.1038/s41440-020-0470-9] [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] [Received: 12/17/2019] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 02/07/2023]
Abstract
The nucleus tractus solitarius (NTS), paraventricular nucleus (PVN), and rostral ventrolateral medulla (RVLM) are the most targeted regions of central blood pressure control studies. Glutamate and gamma-aminobutyric acid (GABA) interact within these brain regions to modulate blood pressure. The brain renin-angiotensin system also participates in central blood pressure control. Angiotensin II increases blood pressure through the stimulation of angiotensin II type 1 (AT1) receptors within the PVN and RVLM and attenuates baroreceptor sensitivity, resulting in elevated blood pressure within the NTS. Angiotensin II type 2 (AT2) receptors in cardiovascular control centers in the brain also appear to be involved in blood pressure control and counteract AT1 receptor-mediated effects. The current review is focused on the interaction of GABA with AT1 and AT2 receptors in the control of blood pressure within the RVLM, PVN and NTS. Within the NTS, GABA is released from local GABAergic interneurons that are stimulated by local AT1 receptors and mediates a hypertensive response. In contrast, the local increase in GABA levels observed after AT2 receptor stimulation within the RVLM, likely from GABAergic nerve endings originating in the caudal ventrolateral medulla, is important in the mediation of the hypotensive response. Preliminary results suggest that the hypertensive response to AT1 receptor stimulation within the RVLM is associated with a reduction in GABA release. The current experimental evidence therefore indicates that GABA is an important mediator of brainstem responses to AT1 and AT2 receptor stimulation and that increased GABA release may play a role in hypertensive and hypotensive responses, depending on the site of action.
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Affiliation(s)
- Alain G Dupont
- Department of Pharmacology, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences, (C4N) Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, 1090, Belgium
| | - Laura Légat
- Department of Pharmacology, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences, (C4N) Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, 1090, Belgium.
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De Lange-Jacobs P, Shaikh-Kader A, Thomas B, Nyakudya TT. An Overview of the Potential Use of Ethno-Medicinal Plants Targeting the Renin-Angiotensin System in the Treatment of Hypertension. Molecules 2020; 25:E2114. [PMID: 32366012 PMCID: PMC7249071 DOI: 10.3390/molecules25092114] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/15/2020] [Accepted: 04/22/2020] [Indexed: 01/09/2023] Open
Abstract
The development of risk factors associated with cardiovascular disorders present a major public health challenge in both developed countries and countries with emerging economies. Hypertension and associated complications including stroke and myocardial infarction have reached pandemic levels. Current management strategies of hypertension predominantly include the utilization of pharmaceutical drugs which are often associated with undesirable side effects. Moreover, the drugs are often too expensive for populations from resource-limited Southern African rural, and some urban, communities. As a result, most patients rely on ethno-medicinal plants for the treatment of a variety of diseases including cardiovascular and metabolic disorders. The effectiveness of these plants in managing several cardiovascular diseases has been attributed to the presence of bioactive phytochemical constituents. In this review, the treatment options that target the renin-angiotensin system (RAS) in the management of hypertension were summarized, with special emphasis on ethno-medicinal plants and their influence on the ACE1 RAS pathway. The dearth of knowledge regarding the effect of ethno-medicinal plants on the ACE2 pathway was also highlighted.
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Affiliation(s)
- Pietro De Lange-Jacobs
- Department of Human Anatomy and Physiology, University of Johannesburg, Doornfontein Campus, Corner Beit and Siemert Streets, Doornfontein, Johannesburg 2000, South Africa; (P.D.L.-J.); (A.S.-K.); (B.T.)
| | - Asma Shaikh-Kader
- Department of Human Anatomy and Physiology, University of Johannesburg, Doornfontein Campus, Corner Beit and Siemert Streets, Doornfontein, Johannesburg 2000, South Africa; (P.D.L.-J.); (A.S.-K.); (B.T.)
| | - Bianca Thomas
- Department of Human Anatomy and Physiology, University of Johannesburg, Doornfontein Campus, Corner Beit and Siemert Streets, Doornfontein, Johannesburg 2000, South Africa; (P.D.L.-J.); (A.S.-K.); (B.T.)
| | - Trevor T. Nyakudya
- Department of Human Anatomy and Physiology, University of Johannesburg, Doornfontein Campus, Corner Beit and Siemert Streets, Doornfontein, Johannesburg 2000, South Africa; (P.D.L.-J.); (A.S.-K.); (B.T.)
- Department of Physiology, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
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11
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Assersen KB, Sumners C, Steckelings UM. The Renin-Angiotensin System in Hypertension, a Constantly Renewing Classic: Focus on the Angiotensin AT 2-Receptor. Can J Cardiol 2020; 36:683-693. [PMID: 32389341 DOI: 10.1016/j.cjca.2020.02.095] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023] Open
Abstract
It is common knowledge that the renin-angiotensin system (RAS), in particular angiotensin II acting through the angiotensin AT1-receptor (AT1R), is pivotal for the regulation of blood pressure (BP) and extracellular volume. More recent findings have revealed that the RAS is far more complex than initially thought and that it harbours additional mediators and receptors, which are able to counteract and thereby fine-tune AT1R-mediated actions. This review will focus on the angiotensin AT2-receptor (AT2R), which is one of the "counter-regulatory" receptors within the RAS. It will review and discuss data related to the role of the AT2R in regulation of BP and focus on the following 3 questions: Do peripheral AT2R have an impact on BP regulation, and, if so, does this effect become apparent only under certain conditions? Are central nervous system AT2R involved in regulation of BP, and, if so, which brain areas are involved and what are the mechanisms? Does dysfunction of AT2R contribute to the pathogenesis of hypertension in preeclampsia?
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Affiliation(s)
- Kasper B Assersen
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - U Muscha Steckelings
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark.
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12
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Otani K, Yokoya M, Fujioka Y, Okada M, Yamawaki H. Small extracellular vesicles from rat plasma promote migration and proliferation of vascular smooth muscle cells. J Vet Med Sci 2020; 82:299-306. [PMID: 31902833 PMCID: PMC7118471 DOI: 10.1292/jvms.19-0643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Small extracellular vesicles (sEV) contain various molecules and mediate cell-to-cell
communication under both physiological and pathological conditions. We have recently
reported that sEV isolated from plasma of normotensive Wistar Kyoto rats (WKY) and
spontaneously hypertensive rats (SHR) regulate systemic blood pressure. The initiation and
development of hypertension partly rely on proliferation and migration of vascular smooth
muscle cells (SMCs) followed by the structural remodeling of vascular wall. In the present
study, we examined the effects of plasma sEV in WKY and SHR on the proliferative and
migratory functions of primary rat aortic SMCs. There was no difference in the
concentration and size distribution of plasma sEV between WKY and SHR, while the protein
expression of CD81 in plasma sEV from SHR was lower than that from WKY. Both plasma sEV
from WKY and SHR were internalized into SMCs and stimulated the migration and
proliferation with a similar potency. In summary, we, for the first time, demonstrated
that plasma sEV in WKY and SHR are physiologically active in terms of proliferative and
migratory functions, however, these effects do not seem to be related to the pathogenesis
of hypertension development.
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Affiliation(s)
- Kosuke Otani
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
| | - Mai Yokoya
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
| | - Yusei Fujioka
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
| | - Muneyoshi Okada
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
| | - Hideyuki Yamawaki
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
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13
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Sandgren JA, Linggonegoro DW, Zhang SY, Sapouckey SA, Claflin KE, Pearson NA, Leidinger MR, Pierce GL, Santillan MK, Gibson-Corley KN, Sigmund CD, Grobe JL. Angiotensin AT 1A receptors expressed in vasopressin-producing cells of the supraoptic nucleus contribute to osmotic control of vasopressin. Am J Physiol Regul Integr Comp Physiol 2018; 314:R770-R780. [PMID: 29364700 PMCID: PMC6032302 DOI: 10.1152/ajpregu.00435.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/03/2018] [Accepted: 01/17/2018] [Indexed: 11/22/2022]
Abstract
Angiotensin II (ANG) stimulates the release of arginine vasopressin (AVP) from the neurohypophysis through activation of the AT1 receptor within the brain, although it remains unclear whether AT1 receptors expressed on AVP-expressing neurons directly mediate this control. We explored the hypothesis that ANG acts through AT1A receptors expressed directly on AVP-producing cells to regulate AVP secretion. In situ hybridization and transgenic mice demonstrated localization of AVP and AT1A mRNA in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN), but coexpression of both AVP and AT1A mRNA was only observed in the SON. Mice harboring a conditional allele for the gene encoding the AT1A receptor (AT1Aflox) were then crossed with AVP-Cre mice to generate mice that lack AT1A in all cells that express the AVP gene (AT1AAVP-KO). AT1AAVP-KO mice exhibited spontaneously increased plasma and serum osmolality but no changes in fluid or salt-intake behaviors, hematocrit, or total body water. AT1AAVP-KO mice exhibited reduced AVP secretion (estimated by measurement of copeptin) in response to osmotic stimuli such as acute hypertonic saline loading and in response to chronic intracerebroventricular ANG infusion. However, the effects of these receptors on AVP release were masked by complex stimuli such as overnight dehydration and DOCA-salt treatment, which simultaneously induce osmotic, volemic, and pressor stresses. Collectively, these data support the expression of AT1A in AVP-producing cells of the SON but not the PVN, and a role for AT1A receptors in these cells in the osmotic regulation of AVP secretion.
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MESH Headings
- Angiotensin II/administration & dosage
- Angiotensin II/pharmacology
- Animals
- Body Water
- Feeding Behavior
- Injections, Intraventricular
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Osmosis
- Paraventricular Hypothalamic Nucleus/metabolism
- Receptor, Angiotensin, Type 1/biosynthesis
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/physiology
- Sodium, Dietary
- Supraoptic Nucleus/metabolism
- Supraoptic Nucleus/physiology
- Vasoconstrictor Agents/administration & dosage
- Vasoconstrictor Agents/pharmacology
- Vasopressins/biosynthesis
- Vasopressins/physiology
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Affiliation(s)
| | | | - Shao Yang Zhang
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
| | | | | | - Nicole A Pearson
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
| | | | - Gary L Pierce
- Department of Health and Human Physiology, University of Iowa , Iowa City, Iowa
- Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- François M. Abboud Cardiovascular Research Center, University of Iowa , Iowa City, Iowa
| | - Mark K Santillan
- Department of Obstetrics and Gynecology, University of Iowa , Iowa City, Iowa
- Center for Hypertension Research, University of Iowa , Iowa City, Iowa
| | - Katherine N Gibson-Corley
- Department of Pathology, University of Iowa , Iowa City, Iowa
- Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- Fraternal Order of Eagles' Diabetes Research Center, University of Iowa , Iowa City, Iowa
| | - Curt D Sigmund
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
- Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- François M. Abboud Cardiovascular Research Center, University of Iowa , Iowa City, Iowa
| | - Justin L Grobe
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
- Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- François M. Abboud Cardiovascular Research Center, University of Iowa , Iowa City, Iowa
- Iowa Neuroscience Institute, University of Iowa , Iowa City, Iowa
- Obesity Research and Education Initiative, University of Iowa , Iowa City, Iowa
- Fraternal Order of Eagles' Diabetes Research Center, University of Iowa , Iowa City, Iowa
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14
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Roncari CF, Barbosa RM, Vendramini RC, De Luca LA, Menani JV, Colombari E, Colombari DSA. Enhanced angiotensin II induced sodium appetite in renovascular hypertensive rats. Peptides 2018; 101:82-88. [PMID: 29305157 DOI: 10.1016/j.peptides.2017.12.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/15/2017] [Accepted: 12/27/2017] [Indexed: 12/12/2022]
Abstract
Renovascular hypertensive 2-kidney, 1-clip (2K1C) rats have an increased activity of the renin-angiotensin system and an initial transitory increase in daily water and NaCl intake. However, the dipsogenic and natriorexigenic responses to angiotensin II (ANG II) have not been tested yet in 2K1C rats. Therefore, in the present study, we evaluated water and 0.3 M NaCl intake induced by water deprivation (WD)-partial rehydration (PR) or intracerebroventricular (icv) ANG II in 2K1C rats. In addition, the cardiovascular changes to these treatments were also evaluated. Male Holtzman rats received a silver clip around the left renal artery to induce 2K1C renovascular hypertension. In the 5th week, a group of animals received a guide cannula in the lateral ventricle for icv injections. Daily water intake increased from the 3rd week after surgery and remained elevated until the 6th week (last recording week), whereas daily 0.3 M NaCl intake transiently increased from the 2nd to the 5th week after surgery. On the 6th week, in spite of comparable daily 0.3 M NaCl intake between 2K1C and sham rats, WD-PR and icv ANG II induced an increased 0.3 M NaCl intake in 2K1C rats. Water intake induced by WD-PR, not by icv ANG II, also increased in 2K1C rats. The increase in arterial pressure to WD-PR or icv ANG II was similar in sham and 2K1C rats. Therefore, these results suggest that 2K1C rats are more responsive to the natriorexigenic effects of ANG II, whereas other responses to ANG II are not modified.
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Affiliation(s)
- Camila F Roncari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil.
| | - Rafaela M Barbosa
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - Regina C Vendramini
- Department of Clinical Analysis, School of Pharmacy, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - Laurival A De Luca
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - José V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
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15
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Nielsen PM, Grimm D, Wehland M, Simonsen U, Krüger M. The Combination of Valsartan and Sacubitril in the Treatment of Hypertension and Heart Failure - an Update. Basic Clin Pharmacol Toxicol 2017; 122:9-18. [DOI: 10.1111/bcpt.12912] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Peter Munch Nielsen
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
| | - Daniela Grimm
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
| | - Markus Wehland
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
| | - Ulf Simonsen
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
| | - Marcus Krüger
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
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16
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Wang K, Xu Y, Yang W, Zhang Y. Insufficient hypothalamic angiotensin-converting enzyme 2 is associated with hypertension in SHR rats. Oncotarget 2017; 8:20244-20251. [PMID: 28423630 PMCID: PMC5386759 DOI: 10.18632/oncotarget.15666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 01/03/2017] [Indexed: 12/29/2022] Open
Abstract
Angiotensin-Converting Enzyme 2 (ACE2) is a key enzyme in the renin-angiotensin system (RAS), which is implicated in the pathogenesis of hypertension and other cardiovascular diseases. In this study we investigated the expression of ACE2 in the hypothalamus and pituitary tissues and its relationship to hypertension by comparing them in male WKY and SHR rats. We observed that the plasma levels of corticotrophin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and aldosterone (ALD) were all lower in SHR than WKY rats (P<0.05), whereas plasma angiotensin II (AngII) levels were higher in SHR rats (P<0.05). Levels of ACE mRNA and protein were higher in the hypothalamus of SHR than WKY rats (P<0.05). By contrast, hypothalamic expression of ACE2 protein was lower in SHR rats (P<0.05), despite comparable mRNA levels in SHR and WKY rats. There were no differences in the expression levels of ACE, ACE2, AT1 or Mas mRNA in the pituitaries of SHR and WKY rats (P>0.05). These results suggest that insufficiency of hypothalamic ACE2 is associated with hypertension in SHR rats.
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Affiliation(s)
- Kun Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanyuan Xu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiwei Yang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanshu Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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17
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Steckelings UM, Kloet AD, Sumners C. Centrally Mediated Cardiovascular Actions of the Angiotensin II Type 2 Receptor. Trends Endocrinol Metab 2017; 28:684-693. [PMID: 28733135 PMCID: PMC5563271 DOI: 10.1016/j.tem.2017.06.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/06/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023]
Abstract
Sustained increases in the activity of the sympathetic neural pathways that exit the brain and which increase blood pressure (BP) are a major underlying factor in resistant hypertension. Recently available information on the occurrence of angiotensin II type 2 receptors (AT2Rs) within or adjacent to brain cardiovascular control centers is consistent with findings that stimulation of these receptors lowers BP, particularly during hypertension of neurogenic origin. Until recently brain AT2R had not been considered by many to play a role in the central control of BP. Demonstration of these powerful antihypertensive effects of brain AT2R opens the door to reconsideration of their role in BP regulation, and their consideration as a novel therapeutic avenue for resistant hypertension.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine (IMM), Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Annette de Kloet
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA.
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18
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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: 5.9] [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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19
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Agassandian K, Grobe JL, Liu X, Agassandian M, Thompson AP, Sigmund CD, Cassell MD. Evidence for intraventricular secretion of angiotensinogen and angiotensin by the subfornical organ using transgenic mice. Am J Physiol Regul Integr Comp Physiol 2017; 312:R973-R981. [PMID: 28490451 PMCID: PMC5495920 DOI: 10.1152/ajpregu.00511.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/03/2017] [Accepted: 05/03/2017] [Indexed: 01/05/2023]
Abstract
Direct intracerebroventricular injection of angiotensin II (ANG II) causes increases in blood pressure and salt and water intake, presumably mimicking an effect mediated by an endogenous mechanism. The subfornical organ (SFO) is a potential source of cerebrospinal fluid (CSF), ANG I, and ANG II, and thus we hypothesized that the SFO has a secretory function. Endogenous levels of angiotensinogen (AGT) and renin are very low in the brain. We therefore examined the immunohistochemical localization of angiotensin peptides and AGT in the SFO, and AGT in the CSF in two transgenic models that overexpress either human AGT (A+ mice), or both human AGT (hAGT) and human renin (SRA mice) in the brain. Measurements were made at baseline and following volumetric depletion of CSF. Ultrastructural analysis with immunoelectron microscopy revealed that superficially located ANG I/ANG II and AGT immunoreactive cells in the SFO were vacuolated and opened directly into the ventricle. Withdrawal of CSF produced an increase in AGT in the CSF that was accompanied by a large decline in AGT immunoreactivity within SFO cells. Our data provide support for the hypothesis that the SFO is a secretory organ that releases AGT and possibly ANG I/ANG II into the ventricle at least under conditions when genes that control the renin-angiotensin system are overexpressed in mice.
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Affiliation(s)
- Khristofor Agassandian
- Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Justin L Grobe
- UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Xuebo Liu
- UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Marianna Agassandian
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Anthony P Thompson
- Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.,UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Curt D Sigmund
- UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; .,Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Martin D Cassell
- Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.,UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
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20
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Low-level Chronic Lead Exposure Impairs Neural Control of Blood Pressure and Heart Rate in Rats. Cardiovasc Toxicol 2016; 17:190-199. [DOI: 10.1007/s12012-016-9374-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Kwon KC, Daniell H. Oral Delivery of Protein Drugs Bioencapsulated in Plant Cells. Mol Ther 2016; 24:1342-50. [PMID: 27378236 PMCID: PMC5023392 DOI: 10.1038/mt.2016.115] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/29/2016] [Indexed: 12/11/2022] Open
Abstract
Plants cells are now approved by the FDA for cost-effective production of protein drugs (PDs) in large-scale current Good Manufacturing Practice (cGMP) hydroponic growth facilities. In lyophilized plant cells, PDs are stable at ambient temperature for several years, maintaining their folding and efficacy. Upon oral delivery, PDs bioencapsulated in plant cells are protected in the stomach from acids and enzymes but are subsequently released into the gut lumen by microbes that digest the plant cell wall. The large mucosal area of the human intestine offers an ideal system for oral drug delivery. When tags (receptor-binding proteins or cell-penetrating peptides) are fused to PDs, they efficiently cross the intestinal epithelium and are delivered to the circulatory or immune system. Unique tags to deliver PDs to human immune or nonimmune cells have been developed recently. After crossing the epithelium, ubiquitous proteases cleave off tags at engineered sites. PDs are also delivered to the brain or retina by crossing the blood–brain or retinal barriers. This review highlights recent advances in PD delivery to treat Alzheimer's disease, diabetes, hypertension, Gaucher's or ocular diseases, as well as the development of affordable drugs by eliminating prohibitively expensive purification, cold chain and sterile delivery.
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Affiliation(s)
- Kwang-Chul Kwon
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Henry Daniell
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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22
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Anderson WD, Makadia HK, Vadigepalli R. Molecular variability elicits a tunable switch with discrete neuromodulatory response phenotypes. J Comput Neurosci 2016; 40:65-82. [PMID: 26621106 PMCID: PMC4867553 DOI: 10.1007/s10827-015-0584-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 10/28/2015] [Accepted: 11/02/2015] [Indexed: 01/08/2023]
Abstract
Recent single cell studies show extensive molecular variability underlying cellular responses. We evaluated the impact of molecular variability in the expression of cell signaling components and ion channels on electrophysiological excitability and neuromodulation. We employed a computational approach that integrated neuropeptide receptor-mediated signaling with electrophysiology. We simulated a population of neurons in which expression levels of a neuropeptide receptor and multiple ion channels were simultaneously varied within a physiological range. We analyzed the effects of variation on the electrophysiological response to a neuropeptide stimulus. Our results revealed distinct response patterns associated with low versus high receptor levels. Neurons with low receptor levels showed increased excitability and neurons with high receptor levels showed reduced excitability. These response patterns were separated by a narrow receptor level range forming a separatrix. The position of this separatrix was dependent on the expression levels of multiple ion channels. To assess the relative contributions of receptor and ion channel levels to the response profiles, we categorized the responses into six phenotypes based on response kinetics and magnitude. We applied several multivariate statistical approaches and found that receptor and channel expression levels influence the neuromodulation response phenotype through a complex though systematic mapping. Our analyses extended our understanding of how cellular responses to neuromodulation vary as a function of molecular expression. Our study showed that receptor expression and biophysical state interact with distinct relative contributions to neuronal excitability.
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Affiliation(s)
- Warren D Anderson
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA
- Graduate program in Neuroscience, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA
| | - Hirenkumar K Makadia
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA
| | - Rajanikanth Vadigepalli
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA.
- Graduate program in Neuroscience, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA.
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust St, Philadelphia, PA, 19107, USA.
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Ferreira PM, Xavier CH, Alzamora AC, Santos RAS, Campagnole-Santos MJ. Differential control of vasomotion by angiotensins in the rostral ventrolateral medulla of hypertensive rats. Neuropeptides 2015; 53:11-8. [PMID: 26390943 DOI: 10.1016/j.npep.2015.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 08/25/2015] [Accepted: 09/08/2015] [Indexed: 11/19/2022]
Abstract
The central and peripheral renin-angiotensin systems are known for playing a key role in cardiovascular control. In the present study, we evaluated the hemodynamic effects produced by nanoinjections of angiotensin II (Ang II) or angiotensin-(1-7) [Ang-(1-7)] into the rostral ventrolateral medulla (RVLM) of adult male normotensive (Wistar-WT) and spontaneously hypertensive rats (SHR). Animals were anesthetized (urethane 1.2g/kg) and instrumented for recording blood pressure (BP), heart rate (HR) and blood flow (BF) in the femoral, renal or mesenteric arteries. Afterwards, rats were positioned in a stereotaxic and prepared for nanoinjections (100 nl) of saline (NaCl 0.9%), Ang-(1-7) (40 ng) or Ang II (40 ng) into the RVLM. The vascular resistance (VR) was calculated by ΔMAP/ΔBF ratio. In WT, Ang-(1-7) or Ang II caused equipotent pressor effects that were not accompanied by changes in vascular resistance. However, MAP changes were greater in SHR. This strain also showed a concomitant increase in relative vascular resistance (ΔVR/VRbaseline) of renal (0.31 ± 0.07 and 0.3 ± 0.07 vs. 0.02 ± 0.01; Ang-(1-7), Ang II and Saline, respectively) and mesenteric beds (0.3 ± 0.06 and 0.33 ± 0.04 vs. 0.05 ± 0.02; Ang-(1-7), Ang II and saline, respectively). We conclude that Ang II and Ang-(1-7) at the RVLM control the vascular resistance of renal and mesenteric beds during hypertension.
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Affiliation(s)
- Patrícia M Ferreira
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil.
| | - Carlos H Xavier
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Andreia C Alzamora
- Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, MG, Brazil
| | - Robson A S Santos
- Instituto Nacional de Ciência e Tecnologia em Nanobiofarmacêutica (INCT-Nanobiofar), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Maria J Campagnole-Santos
- Instituto Nacional de Ciência e Tecnologia em Nanobiofarmacêutica (INCT-Nanobiofar), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
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Multiscale model of dynamic neuromodulation integrating neuropeptide-induced signaling pathway activity with membrane electrophysiology. Biophys J 2015; 108:211-23. [PMID: 25564868 DOI: 10.1016/j.bpj.2014.11.1851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/21/2014] [Accepted: 11/11/2014] [Indexed: 02/07/2023] Open
Abstract
We developed a multiscale model to bridge neuropeptide receptor-activated signaling pathway activity with membrane electrophysiology. Typically, the neuromodulation of biochemical signaling and biophysics have been investigated separately in modeling studies. We studied the effects of Angiotensin II (AngII) on neuronal excitability changes mediated by signaling dynamics and downstream phosphorylation of ion channels. Experiments have shown that AngII binding to the AngII receptor type-1 elicits baseline-dependent regulation of cytosolic Ca(2+) signaling. Our model simulations revealed a baseline Ca(2+)-dependent response to AngII receptor type-1 activation by AngII. Consistent with experimental observations, AngII evoked a rise in Ca(2+) when starting at a low baseline Ca(2+) level, and a decrease in Ca(2+) when starting at a higher baseline. Our analysis predicted that the kinetics of Ca(2+) transport into the endoplasmic reticulum play a critical role in shaping the Ca(2+) response. The Ca(2+) baseline also influenced the AngII-induced excitability changes such that lower Ca(2+) levels were associated with a larger firing rate increase. We examined the relative contributions of signaling kinases protein kinase C and Ca(2+)/Calmodulin-dependent protein kinase II to AngII-mediated excitability changes by simulating activity blockade individually and in combination. We found that protein kinase C selectively controlled firing rate adaptation whereas Ca(2+)/Calmodulin-dependent protein kinase II induced a delayed effect on the firing rate increase. We tested whether signaling kinetics were necessary for the dynamic effects of AngII on excitability by simulating three scenarios of AngII-mediated KDR channel phosphorylation: (1), an increased steady state; (2), a step-change increase; and (3), dynamic modulation. Our results revealed that the kinetics emerging from neuromodulatory activation of the signaling network were required to account for the dynamical changes in excitability. In summary, our integrated multiscale model provides, to our knowledge, a new approach for quantitative investigation of neuromodulatory effects on signaling and electrophysiology.
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Smith JA, Pati D, Wang L, de Kloet AD, Frazier CJ, Krause EG. Hydration and beyond: neuropeptides as mediators of hydromineral balance, anxiety and stress-responsiveness. Front Syst Neurosci 2015; 9:46. [PMID: 25873866 PMCID: PMC4379895 DOI: 10.3389/fnsys.2015.00046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 03/06/2015] [Indexed: 11/13/2022] Open
Abstract
Challenges to body fluid homeostasis can have a profound impact on hypothalamic regulation of stress responsiveness. Deficiencies in blood volume or sodium concentration leads to the generation of neural and humoral signals relayed through the hindbrain and circumventricular organs that apprise the paraventricular nucleus of the hypothalamus (PVH) of hydromineral imbalance. Collectively, these neural and humoral signals converge onto PVH neurons, including those that express corticotrophin-releasing factor (CRF), oxytocin (OT), and vasopressin, to influence their activity and initiate compensatory responses that alleviate hydromineral imbalance. Interestingly, following exposure to perceived threats to homeostasis, select limbic brain regions mediate behavioral and physiological responses to psychogenic stressors, in part, by influencing activation of the same PVH neurons that are known to maintain body fluid homeostasis. Here, we review past and present research examining interactions between hypothalamic circuits regulating body fluid homeostasis and those mediating behavioral and physiological responses to psychogenic stress.
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Affiliation(s)
- Justin A. Smith
- Laboratory of Dr. Eric Krause, Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesville, FL, USA
| | - Dipanwita Pati
- Laboratory of Dr. Charles Frazier, Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesville, FL, USA
| | - Lei Wang
- Laboratory of Dr. Eric Krause, Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesville, FL, USA
| | - Annette D. de Kloet
- Laboratory of Dr. Colin Sumners, Department of Physiology and Functional Genomics, College of Medicine, University of FloridaGainesville, FL, USA
| | - Charles J. Frazier
- Laboratory of Dr. Charles Frazier, Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesville, FL, USA
| | - Eric G. Krause
- Laboratory of Dr. Eric Krause, Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesville, FL, USA
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Hui L, Wu JQ, Ye MJ, Zheng K, He JC, Zhang X, Liu JH, Tian HJ, Gong BH, Chen DC, Lv MH, Soares JC, Zhang XY. Association of angiotensin-converting enzyme gene polymorphism with schizophrenia and depressive symptom severity in a Chinese population. Hum Psychopharmacol 2015; 30:100-7. [PMID: 25694211 DOI: 10.1002/hup.2460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 11/06/2014] [Accepted: 12/05/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND Depressive symptoms are frequently observed in schizophrenia patients. Angiotensin-converting enzyme (ACE), a key enzyme of renin-angiotensin system, can catalyze the degradation of neuropeptides and modulate dopaminergic and serotonergic neurotransmission. Previous studies have revealed the association of the ACE gene insertion/deletion polymorphism with depressive disorder and its treatment response but not with the depressive symptoms in schizophrenia. OBJECTIVE The aim of this study is to examine whether this polymorphism was associated with susceptibility to schizophrenia and with its psychopathological symptoms, especially depressive symptoms in a Han Chinese population. METHODS This polymorphism was genotyped in 382 chronic patients and 538 healthy controls. Psychopathology was characterised using the positive and negative syndrome scale. RESULTS The allelic and genotypic frequencies of this polymorphism significantly differed between patients and controls (both p < 0.001). A significant difference in the positive and negative syndrome scale depressive symptom score was observed among the three genotypes (p < 0.03), with higher score in patients with insertion/insertion (I/I) than with deletion/deletion (D/D) genotypes (p < 0.05). Furthermore, there was a significant linear correlation between the number of I alleles and the depressive symptom score (p < 0.05). CONCLUSIONS The ACE gene insertion/deletion polymorphism may play a role in susceptibility to schizophrenia and also in its depressive symptom severity in a Han Chinese population.
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Affiliation(s)
- Li Hui
- Institute of Kangning Mental Health, Wenzhou Kangning Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
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Opposite effects of oxytocin on water intake induced by hypertonic NaCl or polyethylene glycol administration. Physiol Behav 2015; 141:135-42. [PMID: 25617595 DOI: 10.1016/j.physbeh.2015.01.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/20/2014] [Accepted: 01/20/2015] [Indexed: 11/21/2022]
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Basu U, Seravalli J, Madayiputhiya N, Adamec J, Case AJ, Zimmerman MC. Rapid metabolism of exogenous angiotensin II by catecholaminergic neuronal cells in culture media. Physiol Rep 2015; 3:3/2/e12287. [PMID: 25649249 PMCID: PMC4393196 DOI: 10.14814/phy2.12287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Angiotensin II (AngII) acts on central neurons to increase neuronal firing and induce sympathoexcitation, which contribute to the pathogenesis of cardiovascular diseases including hypertension and heart failure. Numerous studies have examined the precise AngII-induced intraneuronal signaling mechanism in an attempt to identify new therapeutic targets for these diseases. Considering the technical challenges in studying specific intraneuronal signaling pathways in vivo, especially in the cardiovascular control brain regions, most studies have relied on neuronal cell culture models. However, there are numerous limitations in using cell culture models to study AngII intraneuronal signaling, including the lack of evidence indicating the stability of AngII in culture media. Herein, we tested the hypothesis that exogenous AngII is rapidly metabolized in neuronal cell culture media. Using liquid chromatography-tandem mass spectrometry, we measured levels of AngII and its metabolites, Ang III, Ang IV, and Ang-1-7, in neuronal cell culture media after administration of exogenous AngII (100 nmol/L) to a neuronal cell culture model (CATH.a neurons). AngII levels rapidly declined in the media, returning to near baseline levels within 3 h of administration. Additionally, levels of Ang III and Ang-1-7 acutely increased, while levels of Ang IV remained unchanged. Replenishing the media with exogenous AngII every 3 h for 24 h resulted in a consistent and significant increase in AngII levels for the duration of the treatment period. These data indicate that AngII is rapidly metabolized in neuronal cell culture media, and replenishing the media at least every 3 h is needed to sustain chronically elevated levels.
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Affiliation(s)
- Urmi Basu
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Javier Seravalli
- Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Nandakumar Madayiputhiya
- Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Jiri Adamec
- Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Adam J Case
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Matthew C Zimmerman
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
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McCarthy CA, Facey LJ, Widdop RE. The protective arms of the renin-angiontensin system in stroke. Curr Hypertens Rep 2015; 16:440. [PMID: 24816974 DOI: 10.1007/s11906-014-0440-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
It is quite well established that activation of the so-called protective arms of the renin-angiotensin system (RAS), involving both AT2 and Mas receptors, provides a counter-regulatory role to AT1 receptor overactivity that may drive pathological changes in the cardiovascular system. In this brief review, we will focus on recent evidence that identifies at least three different pathways that may be effective in the setting of stroke and may be complementary with AT1 receptor blockade. Such mechanisms include AT2 receptor stimulation, Mas receptor stimulation and insulin-regulated aminopeptidase blockade. This report highlights recent data demonstrating striking neuroprotective effects in preclinical models of stroke targeting each of these pathways, which may pave the way for translational opportunities in this field.
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Affiliation(s)
- Claudia A McCarthy
- Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
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Metoprolol restores expression and vasodilatation function of AT2R in spontaneously hypertensive rats. J Cardiovasc Pharmacol 2014; 63:252-8. [PMID: 24193197 DOI: 10.1097/fjc.0000000000000042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin II type 2 receptor (AT2R) is thought as an important regulatory target during antihypertensive treatment but its role in vasomotor regulation remains controversial. The interactional relationship between the sympathetic nervous systems and the renin-angiotensin-aldosterone system (RAS) has been revealed but poorly investigated. This work was designed to explore the effect of metoprolol (MET) treatment on the RAS, especially the expression and vasomotor function of AT2R, in spontaneously hypertensive rats (SHR). The results showed that upregulated renin activity and Ang II concentration of plasma in SHR were inhibited by MET treatment. In isolated superior mesenteric arteries from both Wistar-Kyoto rats and SHR, Ang II perfusion induced vasodilatation after AT1R inhibition by telmisartan, although the vasodilatation was harmed in SHR. Furthermore, AT2R inhibitor PD123319 arrested the vasodilatation induced by Ang II. SHR received MET exerted improved vasodilatation mediated by AT2R (47.29% ± 5.16% vs. 24.99% ± 4.93% for MET and SHR, respectively; P < 0.05). Western blot analysis showed that MET restored expression of AT2R in SHR, which may contribute to MET's antihypertensive effect. These results suggested an impact of β-adrenergic blocker on RAS and supported an important role of AT2R in antihypertensive treatment.
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31
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Drapala A, Sikora M, Ufnal M. Statins, the renin–angiotensin–aldosterone system and hypertension – a tale of another beneficial effect of statins. J Renin Angiotensin Aldosterone Syst 2014; 15:250-8. [DOI: 10.1177/1470320314531058] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Adrian Drapala
- Department of Experimental and Clinical Physiology, Medical University of Warsaw, Poland
| | - Mariusz Sikora
- Department of Experimental and Clinical Physiology, Medical University of Warsaw, Poland
| | - Marcin Ufnal
- Department of Experimental and Clinical Physiology, Medical University of Warsaw, Poland
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Affiliation(s)
- Robson Augusto Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, CEP 31270-910, Brazil.
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Park MH, Kim HN, Lim JS, Ahn JS, Koh JY. Angiotensin II potentiates zinc-induced cortical neuronal death by acting on angiotensin II type 2 receptor. Mol Brain 2013; 6:50. [PMID: 24289788 PMCID: PMC4222118 DOI: 10.1186/1756-6606-6-50] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/26/2013] [Indexed: 01/19/2023] Open
Abstract
Background The angiotensin system has several non-vascular functions in the central nervous system. For instance, inhibition of the brain angiotensin system results in a reduction in neuronal death following acute brain injury such as ischemia and intracerebral hemorrhage, even under conditions of constant blood pressure. Since endogenous zinc has been implicated as a key mediator of ischemic neuronal death, we investigated the possibility that the angiotensin system affects the outcome of zinc-triggered neuronal death in cortical cell cultures. Results Exposure of cortical cultures containing neurons and astrocytes to 300 μM zinc for 15 min induced submaximal death in both types of cells. Interestingly, addition of angiotensin II significantly enhanced the zinc-triggered neuronal death, while leaving astrocytic cell death relatively unchanged. Both type 1 and 2 angiotensin II receptors (AT1R and AT2R, respectively) were expressed in neurons as well as astrocytes. Zinc neurotoxicity was substantially attenuated by PD123319, a specific inhibitor of AT2R, and augmented by CGP42112, a selective activator of AT2R, indicating a critical role for this receptor subtype in the augmentation of neuronal cell death. Because zinc toxicity occurs largely through oxidative stress, the levels of superoxides in zinc-treated neurons were assessed by DCF fluorescence microscopy. Combined treatment with zinc and angiotensin II substantially increased the levels of superoxides in neurons compared to those induced by zinc alone. This increase in oxidative stress by angiotensin II was completely blocked by the addition of PD123319. Finally, since zinc-induced oxidative stress may be caused by induction and/or activation of NADPH oxidase, the activation status of Rac and the level of the NADPH oxidase subunit p67phox were measured. Angiotensin II markedly increased Rac activity and the levels of p67phox in zinc-treated neurons and astrocytes in a PD123319-dependent manner. Conclusion The present study shows that the angiotensin system, especially that involving AT2R, may have an oxidative injury-potentiating effect via augmentation of the activity of NADPH oxidase. Hence, blockade of angiotensin signaling cascades in the brain may prove useful in protecting against the oxidative neuronal death that is likely to occur in acute brain injury.
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Affiliation(s)
- Mi-Ha Park
- Neural Injury Research Lab, University of Ulsan College of Medicine, Seoul 138-736, South Korea.
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Kangussu LM, Almeida-Santos AF, Bader M, Alenina N, Fontes MAP, Santos RA, Aguiar DC, Campagnole-Santos MJ. Angiotensin-(1-7) attenuates the anxiety and depression-like behaviors in transgenic rats with low brain angiotensinogen. Behav Brain Res 2013; 257:25-30. [DOI: 10.1016/j.bbr.2013.09.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/27/2013] [Accepted: 09/01/2013] [Indexed: 10/26/2022]
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Chan SHH, Chan JYH. Angiotensin-generated reactive oxygen species in brain and pathogenesis of cardiovascular diseases. Antioxid Redox Signal 2013; 19:1074-84. [PMID: 22429119 DOI: 10.1089/ars.2012.4585] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
SIGNIFICANCE Overproduction of angiotensin II (Ang II) in brain contributes to the pathogenesis of cardiovascular diseases. One of the most promising theses that emerged during the last decade is that production of reactive oxygen species (ROS) and activation of redox-dependent signaling cascades underlie those Ang II actions. This review summarizes our status of understanding on the roles of ROS and redox-sensitive signaling in brain Ang II-dependent cardiovascular diseases, using hypertension and heart failure as illustrative examples. RECENT ADVANCES ROS generated by NADPH oxidase, mitochondrial electron transport chain, and proinflammatory cytokines activates mitogen-activated protein kinases and transcription factors, which in turn modulate ion channel functions and ultimately increase neuronal activity and sympathetic outflow in brain Ang II-dependent cardiovascular diseases. Antioxidants targeting ROS have been demonstrated to be beneficial to Ang II-induced hypertension and heart failure via protection from oxidative stress in brain regions that subserve cardiovascular regulation. CRITICAL ISSUES Intra-neuronal signaling and the downstream redox-sensitive proteins involved in controlling the neuronal discharge rate, the sympathetic outflow, and the pathogenesis of cardiovascular diseases need to be identified. The cross talk between Ang II-induced oxidative stress and neuroinflammation in neural mechanisms of cardiovascular diseases also warrants further elucidation. FUTURE DIRECTIONS Future studies are needed to identify new redox-based therapeutics that work not only in animal models, but also in patients suffering from the prevalent diseases. Upregulation of endogenous antioxidants in the regulation of ROS homeostasis is a potential therapeutic target, as are small molecule- or nanoformulated conjugate-based antioxidant therapy.
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Affiliation(s)
- Samuel H H Chan
- Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital , Kaohsiung, Taiwan, Republic of China
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Abstract
SIGNIFICANCE The renin-angiotensin system (RAS) plays an important role in the normal control of cardiovascular and renal function in the healthy state and is a contributing factor in the development and progression of various types of cardiovascular diseases (CVD), including hypertension, diabetes, and heart failure. RECENT ADVANCES Evidence suggests that a balance between activation of the ACE/Ang II/AT1 receptor axis and the ACE2/Ang-(1-7)/Mas receptor axis is important for the function of the heart, kidney, and autonomic nervous system control of the circulation in the normal healthy state. An imbalance in these opposing pathways toward the ACE/Ang II/AT1 receptor axis is associated with CVD. The key component of this imbalance with respect to neural control of the circulation is the negative interaction between oxidative and NO• mechanisms, which leads to enhanced sympathetic tone and activation in disease conditions such as hypertension and heart failure. CRITICAL ISSUES The key mechanisms that disrupt normal regulation of Ang II and Ang-(1-7) signaling and promote pathogenesis of CVD at all organ levels remain poorly understood. The reciprocal relation between ACE and ACE2 expression and function suggests they are controlled interdependently at pre- and post-translational levels. Insights from neural studies suggest that an interaction between oxidative and nitrosative pathways may be key. FUTURE DIRECTIONS The role of redox mechanisms in the control of expression and activity of RAS enzymes and Ang receptors may provide important insight into the function of local tissue RAS in health and disease.
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Affiliation(s)
- Kaushik P Patel
- 1 Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
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37
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Du D, Chen J, Liu M, Zhu M, Jing H, Fang J, Shen L, Zhu D, Yu J, Wang J. The effects of angiotensin II and angiotensin-(1-7) in the rostral ventrolateral medulla of rats on stress-induced hypertension. PLoS One 2013; 8:e70976. [PMID: 23967142 PMCID: PMC3743893 DOI: 10.1371/journal.pone.0070976] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 06/26/2013] [Indexed: 12/03/2022] Open
Abstract
We have shown that angiotensin II (Ang II) and angiotensin-(1–7) [Ang-(1–7)] increased arterial blood pressure (BP) via glutamate release when microinjected into the rostral ventrolateral medulla (RVLM) in normotensive rats (control). In the present study, we tested the hypothesis that Ang II and Ang-(1–7) in the RVLM are differentially activated in stress-induced hypertension (SIH) by comparing the effects of microinjection of Ang II, Ang-(1–7), and their receptor antagonists on BP and amino acid release in SIH and control rats. We found that Ang II had greater pressor effect, and more excitatory (glutamate) and less inhibitory (taurine and γ-aminobutyric acid) amino acid release in SIH than in control animals. Losartan, a selective AT1 receptor (AT1R) antagonist, decreased mean BP in SIH but not in control rats. PD123319, a selective AT2 receptor (AT2R) antagonist, increased mean BP in control but not in SIH rats. However, Ang-(1–7) and its selective Mas receptor antagonist Ang779 evoked similar effects on BP and amino acid release in both SIH and control rats. Furthermore, we found that in the RVLM, AT1R, ACE protein expression (western blot) and ACE mRNA (real-time PCR) were significantly higher, whereas AT2R protein, ACE2 mRNA and protein expression were significantly lower in SIH than in control rats. Mas receptor expression was similar in the two groups. The results support our hypothesis and demonstrate that upregulation of Ang II by AT1R, not Ang-(1–7), system in the RVLM causes hypertension in SIH rats by increasing excitatory and suppressing inhibitory amino acid release.
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Affiliation(s)
- Dongshu Du
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Neurobiology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Jun Chen
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Min Liu
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Minxia Zhu
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Haojia Jing
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jie Fang
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Linlin Shen
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Danian Zhu
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jerry Yu
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Pulmonary Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Jin Wang
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
- * E-mail:
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Chao J, Gao J, Parbhu KJK, Gao L. Angiotensin type 2 receptors in the intermediolateral cell column of the spinal cord: negative regulation of sympathetic nerve activity and blood pressure. Int J Cardiol 2013; 168:4046-55. [PMID: 23871345 DOI: 10.1016/j.ijcard.2013.06.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 05/07/2013] [Accepted: 06/30/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Our previous study demonstrated that AT2R in brainstem nuclei participated in the regulation of sympathetic outflow and cardiovascular function. However, the functional significance of AT2R in the intermediolateral cell column (IML) of the thoracic spinal cord in normal rats remains elusive. We hypothesized that AT2R activation in the IML exerts a sympatho-inhibitory effect. METHODS AND RESULTS Using Western-blot analysis, immunohistochemical staining and quantitative real-time PCR, both AT1R and AT2R expressions were detected in the spinal cord. The highest AT2R protein expression was found in the IML, while AT1R expression didn't display regional differences within the gray matter. Microinjection of Ang II into the IML dose-dependently elevated mean blood pressure (MAP, employing a transducer-tipped catheter) and renal sympathetic nerve activity (RSNA, using a pair of platinum-iridium recording electrodes), which were completely abolished by Losartan, and attenuated by TEMPOL and apocynin. Activation of AT2R in the IML with CGP42112 evoked hypotension (ΔMAP: -21 ± 4 mmHg) and sympatho-inhibition (RSNA: 73 ± 3% of baseline), which were completely abolished by PD123319 and l-NAME. Blockade of AT2R in the IML with PD123319 significantly increased MAP (11 ± 1 mmHg) and sympathetic nerve activity (RSNA: 133 ± 13% of baseline). Moreover, PD123319 significantly enhanced the Ang II induced pressor response. Furthermore, in isolated IML neurons, CGP42112 treatment augmented potassium current and decreased resting membrane potential by employing whole-cell patch clamp. CONCLUSION In the normal condition, AT2R in the IML tonically inhibits sympathetic activity through an NO/NOS dependent pathway and subsequent potassium channel activation.
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Affiliation(s)
- Jie Chao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
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Narayanaswami V, Somkuwar SS, Horton DB, Cassis LA, Dwoskin LP. Angiotensin AT1 and AT2 receptor antagonists modulate nicotine-evoked [³H]dopamine and [³H]norepinephrine release. Biochem Pharmacol 2013; 86:656-65. [PMID: 23831951 DOI: 10.1016/j.bcp.2013.06.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/24/2013] [Accepted: 06/26/2013] [Indexed: 12/31/2022]
Abstract
Tobacco smoking is the leading preventable cause of death in the United States. A major negative health consequence of chronic smoking is hypertension. Untoward addictive and cardiovascular sequelae associated with chronic smoking are mediated by nicotine-induced activation of nicotinic receptors (nAChRs) within striatal dopaminergic and hypothalamic noradrenergic systems. Hypertension involves both brain and peripheral angiotensin systems. Activation of angiotensin type-1 receptors (AT1) release dopamine and norepinephrine. The current study determined the role of AT1 and angiotensin type-2 (AT2) receptors in mediating nicotine-evoked dopamine and norepinephrine release from striatal and hypothalamic slices, respectively. The potential involvement of nAChRs in mediating effects of AT1 antagonist losartan and AT2 antagonist, 1-[[4-(dimethylamino)-3-methylphenyl]methyl]-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid (PD123319) was evaluated by determining their affinities for α4β2* and α7* nAChRs using [³H]nicotine and [³H]methyllycaconitine binding assays, respectively. Results show that losartan concentration-dependently inhibited nicotine-evoked [³H]dopamine and [³H]norepinephrine release (IC₅₀: 3.9 ± 1.2 and 2.2 ± 0.7 μM; Imax: 82 ± 3 and 89 ± 6%, respectively). In contrast, PD123319 did not alter nicotine-evoked norepinephrine release, and potentiated nicotine-evoked dopamine release. These results indicate that AT1 receptors modulate nicotine-evoked striatal dopamine and hypothalamic norepinephrine release. Furthermore, AT1 receptor activation appears to be counteracted by AT2 receptor activation in striatum. Losartan and PD123319 did not inhibit [³H]nicotine or [³H]methyllycaconitine binding, indicating that these AT1 and AT2 antagonists do not interact with the agonist recognition sites on α4β2* and α7* nAChRs to mediate these effects of nicotine. Thus, angiotensin receptors contribute to the effects of nicotine on dopamine and norepinephrine release in brain regions involved in nicotine reward and hypertension.
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Affiliation(s)
- Vidya Narayanaswami
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone, 465 Biological Pharmaceutical Complex, Lexington, KY 40536-0596, USA
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Yagi S, Akaike M, Ise T, Ueda Y, Iwase T, Sata M. Renin–angiotensin–aldosterone system has a pivotal role in cognitive impairment. Hypertens Res 2013; 36:753-8. [DOI: 10.1038/hr.2013.51] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 01/31/2013] [Accepted: 02/24/2013] [Indexed: 02/07/2023]
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Immunohistochemical Localization of AT1a, AT1b, and AT2 Angiotensin II Receptor Subtypes in the Rat Adrenal, Pituitary, and Brain with a Perspective Commentary. Int J Hypertens 2013; 2013:175428. [PMID: 23573410 PMCID: PMC3614054 DOI: 10.1155/2013/175428] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 11/17/2022] Open
Abstract
Angiotensin II increases blood pressure and stimulates thirst and sodium appetite in the brain. It also stimulates secretion of aldosterone from the adrenal zona glomerulosa and epinephrine from the adrenal medulla. The rat has 3 subtypes of angiotensin II receptors: AT1a, AT1b, and AT2. mRNAs for all three subtypes occur in the adrenal and brain. To immunohistochemically differentiate these receptor subtypes, rabbits were immunized with C-terminal fragments of these subtypes to generate receptor subtype-specific antibodies. Immunofluorescence revealed AT1a and AT2 receptors in adrenal zona glomerulosa and medulla. AT1b immunofluorescence was present in the zona glomerulosa, but not the medulla. Ultrastructural immunogold labeling for the AT1a receptor in glomerulosa and medullary cells localized it to plasma membrane, endocytic vesicles, multivesicular bodies, and the nucleus. AT1b and AT2, but not AT1a, immunofluorescence was observed in the anterior pituitary. Stellate cells were AT1b positive while ovoid cells were AT2 positive. In the brain, neurons were AT1a, AT1b, and AT2 positive, but glia was only AT1b positive. Highest levels of AT1a, AT1b, and AT2 receptor immunofluorescence were in the subfornical organ, median eminence, area postrema, paraventricular nucleus, and solitary tract nucleus. These studies complement those employing different techniques to characterize Ang II receptors.
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Santos KL, Vento MA, Wright JW, Speth RC. The effects of para-chloromercuribenzoic acid and different oxidative and sulfhydryl agents on a novel, non-AT1, non-AT2 angiotensin binding site identified as neurolysin. ACTA ACUST UNITED AC 2013; 184:104-14. [PMID: 23511333 DOI: 10.1016/j.regpep.2013.03.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 12/21/2012] [Accepted: 03/03/2013] [Indexed: 11/28/2022]
Abstract
A novel, non-AT1, non-AT2 brain binding site for angiotensin peptides that is unmasked by p-chloromercuribenzoate (PCMB) has been identified as a membrane associated variant of neurolysin. The ability of different organic and inorganic oxidative and sulfhydryl reactive agents to unmask or inhibit 125I-Sar1Ile8 angiotensin II (SI-Ang II) binding to this site was presently examined. In tissue membranes from homogenates of rat brain and testis incubated in assay buffer containing losartan (10 μM) and PD123319 (10 μM) plus 100 μM PCMB, 5 of the 39 compounds tested inhibited 125I-SI Ang II binding in brain and testis. Mersalyl acid, mercuric chloride (HgCl2) and silver nitrate (AgNO3) most potently inhibited 125I-SI Ang II binding with IC50s ~1-20 μM. This HgCl2 inhibition was independent of any interaction of HgCl2 with angiotensin II (Ang II) based on the lack of effect of HgCl2 on the dipsogenic effects of intracerebroventricularly administered Ang II and 125I-SI Ang II binding to AT1 receptors in the liver. Among sulfhydryl reagents, cysteamine and reduced glutathione (GSH), but not oxidized glutathione (GSSG) up to 1mM, inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis. Thimerosal and 4-hydroxymercuribenzoate moderately inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis at 100 μM; however, they also unmasked non-AT1, non-AT2 binding independent of PCMB. 4-Hydroxybenzoic acid did not promote 125 I-SI Ang II binding to this binding site indicating that only specific organomercurial compounds can unmask the binding site. The common denominator for all of these interacting substances is the ability to bind to protein cysteine sulfur. Comparison of cysteines between neurolysin and the closely related enzyme thimet oligopeptidase revealed an unconserved cysteine (cys650, based on the full length variant) in the proposed ligand binding channel (Brown et al., 2001) [45] near the active site of neurolysin. It is proposed that the mercuric ion in PCMB and closely related organomercurial compounds binds to cys650, while the acidic anion forms an ionic bond with a nearby arginine or lysine along the channel to effect a conformational change in neurolysin that promotes Ang II binding.
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Affiliation(s)
- Kira L Santos
- Pharmaceutical Sciences Department, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328, United States
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Bohlender J, Nussberger J, Imboden H. Angiotensinergic innervation of the kidney: present knowledge and its significance. Curr Hypertens Rep 2012. [PMID: 23197298 DOI: 10.1007/s11906-012-0322-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intrarenal neurotransmission implies the co-release of neuropeptides at the neuro-effector junction with direct influence on parameters of kidney function. The presence of an angiotensin (Ang) II-containing phenotype in catecholaminergic postganglionic and sensory fibers of the kidney, based on immunocytological investigations, has only recently been reported. These angiotensinergic fibers display a distinct morphology and intrarenal distribution, suggesting anatomical and functional subspecialization linked to neuronal Ang II-expression. This review discusses the present knowledge concerning these fibers, and their significance for renal physiology and the pathogenesis of hypertension in light of established mechanisms. The data suggest a new role of Ang II as a co-transmitter stimulating renal target cells or modulating nerve traffic from or to the kidney. Neuronal Ang II is likely to be an independent source of intrarenal Ang II. Further physiological experimentation will have to explore the role of the angiotensinergic renal innervation and integrate it into existing concepts.
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Affiliation(s)
- Jürgen Bohlender
- Hôpital fribourgeois/CHUV and Institute of Cell Biology, University of Bern, Case postale, Fribourg, Switzerland.
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Developmental expression patterns for angiotensin receptors in mouse skin and brain. J Renin Angiotensin Aldosterone Syst 2012. [DOI: 10.1177/1470320312467557] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Hasty AH, Harrison DG. Endoplasmic reticulum stress and hypertension - a new paradigm? J Clin Invest 2012; 122:3859-61. [PMID: 23064369 DOI: 10.1172/jci65173] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Hypertension occurs in approximately 30% of individuals in Western populations and is known to be a major cause of stroke, heart failure, and myocardial infarction. Despite this, the molecular etiology of hypertension remains poorly understood. In this issue of the JCI, Young et al. show that endoplasmic reticulum (ER) stress is an essential signaling event for angiotensin II-induced hypertension in cells of the central nervous system. This provides new insight into the molecular mechanisms that drive hypertension and suggests a potential target for future therapy.
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Affiliation(s)
- Alyssa H Hasty
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA
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Cosentino-Gomes D, Rocco-Machado N, Meyer-Fernandes JR. Cell signaling through protein kinase C oxidation and activation. Int J Mol Sci 2012; 13:10697-10721. [PMID: 23109817 PMCID: PMC3472709 DOI: 10.3390/ijms130910697] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 08/02/2012] [Accepted: 08/13/2012] [Indexed: 01/15/2023] Open
Abstract
Due to the growing importance of cellular signaling mediated by reactive oxygen species (ROS), proteins that are reversibly modulated by these reactant molecules are of high interest. In this context, protein kinases and phosphatases, which act coordinately in the regulation of signal transduction through the phosphorylation and dephosphorylation of target proteins, have been described to be key elements in ROS-mediated signaling events. The major mechanism by which these proteins may be modified by oxidation involves the presence of key redox-sensitive cysteine residues. Protein kinase C (PKC) is involved in a variety of cellular signaling pathways. These proteins have been shown to contain a unique structural feature that is susceptible to oxidative modification. A large number of scientific studies have highlighted the importance of ROS as a second messenger in numerous cellular processes, including cell proliferation, gene expression, adhesion, differentiation, senescence, and apoptosis. In this context, the goal of this review is to discuss the mechanisms by which PKCs are modulated by ROS and how these processes are involved in the cellular response.
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Affiliation(s)
- Daniela Cosentino-Gomes
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil; E-Mails: (N.R.-M.); (J.R.M.-F.)
- Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-21-2562-6781; Fax: +55-21-2270-8647
| | - Nathália Rocco-Machado
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil; E-Mails: (N.R.-M.); (J.R.M.-F.)
- Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil
| | - José Roberto Meyer-Fernandes
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil; E-Mails: (N.R.-M.); (J.R.M.-F.)
- Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil
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Lancien F, Wong M, Arab AA, Mimassi N, Takei Y, Le Mével JC. Central ventilatory and cardiovascular actions of angiotensin peptides in trout. Am J Physiol Regul Integr Comp Physiol 2012; 303:R311-20. [PMID: 22696574 DOI: 10.1152/ajpregu.00145.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the brains of teleosts, angiotensin II (ANG II), one of the main effector peptides of the renin-angiotensin system, is implicated in various physiological functions notably body fluid and electrolyte homeostasis and cardiovascular regulation, but nothing is known regarding the potential action of ANG II and other angiotensin derivatives on ventilation. Consequently, the goal of the present study was to determine possible ventilatory and cardiovascular effects of intracerebroventricular injection of picomole doses (5-100 pmol) of trout [Asn(1)]-ANG II, [Asp(1)]-ANG II, ANG III, ANG IV, and ANG 1-7 into the third ventricle of unanesthetized trout. The central actions of these peptides were also compared with their ventilatory and cardiovascular actions when injected peripherally. Finally, we examined the presence of [Asn(1)]-ANG II, [Asp(1)]-ANG II, ANG III, and ANG IV in the brain and plasma using radioimmunoassay coupled with high-performance liquid chromatography. After intracerebroventricular injection, [Asn(1)]-ANG II and [Asp(1)]-ANG II two ANG IIs, elevated the total ventilation through a selective stimulatory action on the ventilation amplitude. However, the hyperventilatory effect of [Asn(1)]-ANG II was threefold higher than the effect of [Asp(1)]-ANG II at the 50-pmol dose. ANG III, ANG IV, and ANG 1-7 were without effect. In addition, ANG IIs and ANG III increased dorsal aortic blood pressure (P(DA)) and heart rate (HR). After intra-arterial injections, none of the ANG II peptides affected the ventilation but [Asn(1)]-ANG II, [Asp(1)]-ANG II, and ANG III elevated P(DA) (50 pmol: +80%, +58% and +48%, respectively) without significant decrease in HR. In brain tissue, comparable amounts of [Asn(1)]-ANG II and [Asp(1)]-ANG II were detected (ca. 40 fmol/mg brain tissue), but ANG III was not detected, and the amount of ANG IV was about eightfold lower than the content of the ANG IIs. In plasma, ANG IIs were also the major angiotensins (ca. 110 fmol/ml plasma), while significant but lower amounts of ANG III and ANG IV were present in plasma. In conclusion, our study suggests that the two ANG II isoforms produced within the brain may act as a neurotransmitter and/or neuromodulator to regulate the cardioventilatory functions in trout. In the periphery, two ANG IIs and their COOH-terminal peptides may act as a circulating hormone preferentially involved in cardiovascular regulations.
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Affiliation(s)
- Frédéric Lancien
- Laboratoire de Neurophysiologie, SFR ScInBioS, Faculté de Médecine et des Sciences de la Santé, Université Européenne de Bretagne, Université de Brest, INSERM UMR, CHU de Brest, France
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Wright JW, Harding JW. The brain renin–angiotensin system: a diversity of functions and implications for CNS diseases. Pflugers Arch 2012; 465:133-51. [DOI: 10.1007/s00424-012-1102-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 03/20/2012] [Accepted: 03/30/2012] [Indexed: 12/14/2022]
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Murça TM, Almeida TCS, Raizada MK, Ferreira AJ. Chronic activation of endogenous angiotensin-converting enzyme 2 protects diabetic rats from cardiovascular autonomic dysfunction. Exp Physiol 2012; 97:699-709. [PMID: 22286369 DOI: 10.1113/expphysiol.2011.063461] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this study, we evaluated whether the activation of endogenous angiotensin-converting enzyme 2 (ACE2) would improve the cardiovascular autonomic dysfunction of diabetic rats. Ten days after induction of type 1 diabetes (streptozotocin, 50 mg kg(-1) i.v.), the rats were treated orally with 1-[(2-dimethylamino)ethylamino]-4-(hydroxymethyl)-7-[(4-methylphenyl) sulfonyl oxy]-9H-xanthene-9-one (XNT), a newly discovered ACE2 activator (1 mg kg(-1) day(-1)), or saline (equivalent volume) for 30 days. Autonomic cardiovascular parameters were evaluated in conscious animals, and an isolated heart preparation was used to analyse cardiac function. Diabetes induced a significant decrease in the baroreflex bradycardia sensitivity, as well as in the chemoreflex chronotropic response and parasympathetic tone. The XNT treatment improved these parameters by ≈ 76% [0.82 ± 0.09 versus 1.44 ± 0.17 Ratio between changes in pulse interval and changes in mean arterial pressure (ΔPI/ΔmmHg)], ∼85% (-57 ± 9 versus -105 ± 10 beats min(-1)) and ≈ 205% (22 ± 2 versus 66 ± 12 beats min(-1)), respectively. Also, XNT administration enhanced the bradycardia induced by the chemoreflex activation by v 74% in non-diabetic animals (-98 ± 16 versus -170 ± 9 Δbeats min(-1)). No significant changes were observed in the mean arterial pressure, baroreflex tachycardia sensitivity, chemoreflex pressor response and sympathetic tone among any of the groups. Furthermore, chronic XNT treatment ameliorated the cardiac function of diabetic animals. However, the coronary vasoconstriction observed in diabetic rats was unchanged by ACE2 activation. These findings indicate that XNT protects against the autonomic and cardiac dysfunction induced by diabetes. Thus, our results provide evidence for the viability and effectiveness of oral administration of an ACE2 activator for the treatment of the cardiovascular autonomic dysfunction caused by diabetes.
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Affiliation(s)
- Tatiane M Murça
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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Phillips MI, Tang Y. Genetic Modification of Stem Cells for Cardiac, Diabetic, and Hemophilia Transplantation Therapies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 111:285-304. [DOI: 10.1016/b978-0-12-398459-3.00013-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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