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Piťha J, Vaněčková I, Zicha J. Hypertension after the Menopause: What Can We Learn from Experimental Studies? Physiol Res 2023; 72:S91-S112. [PMID: 37565415 PMCID: PMC10660576 DOI: 10.33549/physiolres.935151] [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: 05/11/2023] [Accepted: 06/07/2023] [Indexed: 12/01/2023] Open
Abstract
Hypertension is the most prevalent cardiovascular disease of the adult population and is closely associated with serious cardiovascular events. The burden of hypertension with respect to vascular and other organ damage is greater in women. These sex differences are not fully understood. The unique feature in women is their transition to menopause accompanied by profound hormonal changes that affect the vasculature that are also associated with changes of blood pressure. Results from studies of hormone replacement therapy and its effects on the cardiovascular system are controversial, and the timing of treatment after menopause seems to be important. Therefore, revealing potential sex- and sex hormone-dependent pathophysiological mechanisms of hypertension in experimental studies could provide valuable information for better treatment of hypertension and vascular impairment, especially in postmenopausal women. The experimental rat models subjected to ovariectomy mimicking menopause could be useful tools for studying the mechanisms of blood pressure regulation after menopause and during subsequent therapy.
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Affiliation(s)
- J Piťha
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Elmarakby A, Sullivan J. Sex differences in hypertension: lessons from spontaneously hypertensive rats (SHR). Clin Sci (Lond) 2021; 135:1791-1804. [PMID: 34338771 PMCID: PMC8329852 DOI: 10.1042/cs20201017] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/30/2022]
Abstract
Although numerous clinical and experimental studies have clearly identified a sexual dimorphism in blood pressure control, the mechanism(s) underlying gender differences in blood pressure remain unclear. Over the past two decades, numerous laboratories have utilized the spontaneously hypertensive rats (SHR) as an experimental model of essential hypertension to increase our understanding of the mechanisms regulating blood pressure in males and females. Previous work by our group and others have implicated that differential regulation of adrenergic receptors, the renin-angiotensin system, oxidative stress, nitric oxide bioavailability and immune cells contribute to sex differences in blood pressure control in SHR. The purpose of this review is to summarize previous findings to date regarding the mechanisms of blood pressure control in male versus female SHR.
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Affiliation(s)
- Ahmed A. Elmarakby
- Department of Oral Biology and Diagnostic Sciences, Augusta University, Augusta, GA 30912, U.S.A
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The Influence of Occupational Noise Exposure on Cardiovascular and Hearing Conditions among Industrial Workers. Sci Rep 2019; 9:11524. [PMID: 31395914 PMCID: PMC6687890 DOI: 10.1038/s41598-019-47901-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/18/2019] [Indexed: 12/21/2022] Open
Abstract
This study was conducted to estimate the current prevalence of hypertension, cardiovascular condition and hearing difficulty of workers exposure to occupational noise, and to analyze any associations between these abnormal signs and occupational noise exposure. The subjects included 5205 noise-exposed workers. Workers with high noise exposure were more likely to have a higher threshold value than low exposure ones (P < 0.05). Subjects in the high exposure group had a significantly higher risk of hypertension and hearing loss than the ones in low exposure group. Between the ages of 30 and 45, high-level occupational noise exposure led to a significantly raising risk of both hypertension (Adjusted OR = 1.59, 95% CI, 1.19-2.11) and hearing loss (Adjusted OR = 1.28, 95% CI, 1.03-1.60) when comparing to low-level noise exposure. In male workers, the prevalence of hearing difficulty in high exposure group was approximately 1.2 times worse than in low group (P = 0.006). In addition, exposure to high noise level demonstrated a significant association with hypertension and hearing loss when the duration time to occupational noise was longer than 10 years. Hypertension and hearing difficulty is more prevalent in the noise-exposed group (higher than 85 dB[A]). Steps to reduce workplace noise levels and to improve workplace-based health are thus urgently needed.
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Yamazato M, Nakamoto M, Sakima A, Yamazato Y, Takishita S, Ohya Y. Responsiveness of α2-adrenoceptor/I1-imidazoline receptor in the rostral ventrolateral medulla to cardiovascular regulation is enhanced in conscious spontaneously hypertensive rat. Clin Exp Hypertens 2018; 41:255-262. [PMID: 29764227 DOI: 10.1080/10641963.2018.1469641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Stimulation of α2-adrenoceptor/I1-imidazoline receptors in the rostral ventrolateral medulla decreases the blood pressure via sympathoinhibition. However, alteration of receptor responses in genetically hypertensive rats remains unclear. We examined cardiovascular responses of α2-adrenoceptor/I1-imidazoline receptor agonist and antagonists microinjected into the rostral ventrolateral medulla of conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. Injection of 2-nmol clonidine-an α2-adrenoceptor/I1-imidazoline receptor agonist-unilaterally into the rostral ventrolateral medulla decreased the blood pressure, heart rate, and renal sympathetic nerve activity; the responses were significantly enhanced in spontaneously hypertensive rats than in Wistar Kyoto rats. Co-injection of 2-nmol 2-methoxyidazoxan (a selective α2-adrenoceptor antagonist) or 2-nmol efaroxan (an I1-receptor antagonist) with 2 nmol of clonidine attenuated the hypotensive and bradycardic effects of clonidine-only injection. Injection of 2-methoxyidazoxan alone increased the blood pressure and heart rate in spontaneously hypertensive rats, but not in Wistar Kyoto rats. These results suggest enhanced responsiveness of α2-adrenoceptor/I1-imidazoline receptors in the rostral ventrolateral medulla of spontaneously hypertensive rats.
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Affiliation(s)
- Masanobu Yamazato
- a Department of Cardiovascular Medicine, Nephrology and Neurology , Graduate School of Medicine, University of the Ryukyus , Nishihara-cho, Okinawa , Japan
| | - Minori Nakamoto
- a Department of Cardiovascular Medicine, Nephrology and Neurology , Graduate School of Medicine, University of the Ryukyus , Nishihara-cho, Okinawa , Japan
| | - Atsushi Sakima
- a Department of Cardiovascular Medicine, Nephrology and Neurology , Graduate School of Medicine, University of the Ryukyus , Nishihara-cho, Okinawa , Japan
| | - Yoriko Yamazato
- b Department of Infectious, Respiratory and Digestive Medicine, Faculty of Medicine , University of the Ryukyus , Nishihara-cho, Okinawa , Japan
| | - Shuichi Takishita
- a Department of Cardiovascular Medicine, Nephrology and Neurology , Graduate School of Medicine, University of the Ryukyus , Nishihara-cho, Okinawa , Japan
| | - Yusuke Ohya
- a Department of Cardiovascular Medicine, Nephrology and Neurology , Graduate School of Medicine, University of the Ryukyus , Nishihara-cho, Okinawa , Japan
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Berg T. Kv7(KCNQ)-K +-Channels Influence Total Peripheral Resistance in Female but Not Male Rats, and Hamper Catecholamine Release in Hypertensive Rats of Both Sexes. Front Physiol 2018. [PMID: 29515459 PMCID: PMC5826282 DOI: 10.3389/fphys.2018.00117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
K+-channels of the Kv7/KCNQ-family hyperpolarize and stabilize excitable cells such as autonomic neurons and vascular smooth muscle cells (VSMC). Kv7 may therefore play a role in blood pressure (BP) homeostasis, and prevent a high total peripheral vascular resistance (TPR), a hallmark of hypertensive disease. The present study analyzed if Kv7 channels influence catecholamine release and TPR in normotensive (WKY) and spontaneously hypertensive rats (SHR), and if they may contribute to the antihypertensive protection seen in young, female SHR. Tyramine-stimulated norepinephrine release evokes an adrenergic cardiovascular response, and also allows modulation of release to be reflected in the overflow to plasma. The experiment itself activated some secretion of epinephrine. The results show: (1) XE-991 (Kv7.1-7.4-inhibitor), but not chromanol 293B (Kv7.1-inhibitor), increased tyramine-stimulated norepinephrine overflow and epinephrine secretion in both sexes in SHR, but not WKY. (2) Surprisingly, the Kv7-openers retigabine (Kv7.2-7.5) and ICA-27243 (Kv7.2-7.3-preferring) increased catecholamine release in female SHR. (3) The rise in TPR following tyramine-stimulated norepinephrine release was increased by XE-991 but not chromanol in the female WKY only. (4) Retigabine and ICA-27243 reduced the TPR-response to tyramine in the female SHR only. These results suggested: (1) Up-regulation of Kv7.2-7.3 function in sympathetic neurons and chromaffin cells hampered catecholamine release in SHR of both sexes. (2) The increase catecholamine release observed after channel openers in the female SHR may possibly involve reduced transmission in cholinergic neurons which hamper catecholamine release. These two mechanisms may serve to counter-act the hyperadrenergic state in SHR. (3) Kv7.4, most likely in the vasculature, opposed the tension-response to norepinephrine in the female WKY. (4) Vascular Kv7.4-7.5 could be stimulated and then opposed norepinephrine-induced vasoconstriction in the female SHR. (5) Vascular Kv7 channels did not counter-act norepinephrine induced vasoconstriction in male rats, possibly due to different Kv7 channel regulation. Kv7 channels may represent a novel target for antihypertensive therapy.
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Affiliation(s)
- Torill Berg
- Division of Physiology, Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
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Gao Q, Tang J, Li N, Zhou X, Li Y, Liu Y, Wu J, Yang Y, Shi R, He A, Li X, Zhang Y, Chen J, Zhang L, Sun M, Xu Z. A novel mechanism of angiotensin II-regulated placental vascular tone in the development of hypertension in preeclampsia. Oncotarget 2018; 8:30734-30741. [PMID: 28430615 PMCID: PMC5458163 DOI: 10.18632/oncotarget.15416] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/06/2017] [Indexed: 12/03/2022] Open
Abstract
The present study tested the hypothesis that angiotensin II plays a role in the regulation of placental vascular tone, which contributes to hypertension in preeclampsia. Functional and molecular assays were performed in large and micro placental and non-placental vessels from humans and animals. In human placental vessels, angiotensin II induced vasoconstrictions in 78.7% vessels in 155 tests, as referenced to KCl-induced contractions. In contrast, phenylephrine only produced contractions in 3.0% of 133 tests. In non-placental vessels, phenylephrine induced contractions in 76.0% of 67 tests, whereas angiotensin II failed to produce contractions in 75 tests. Similar results were obtained in animal placental and non-placental vessels. Compared with non-placental vessels, angiotensin II receptors and β -adrenoceptors were significantly increased in placental vessels. Compared to the vessels from normal pregnancy, angiotensin II-induced vasoconstrictions were significantly reduced in preeclamptic placentas, which was associated with a decrease in angiotensin II receptors. In addition, angiotensin II and angiotensin converting enzyme in the maternal-placenta circulation in preeclampsia were increased, whereas angiotensin I and angiotensin1-7 concentrations were unchanged. The study demonstrates a selective effect of angiotensin II in maintaining placental vessel tension, which may play an important role in development of hypertension in preeclampsia.
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Affiliation(s)
- Qinqin Gao
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jiaqi Tang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Na Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiuwen Zhou
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yongmei Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yanping Liu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jue Wu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yuxian Yang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Ruixiu Shi
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Axin He
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yingying Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jie Chen
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Lubo Zhang
- Center for Perinatal Biology, Loma Linda University, Loma Linda, California, USA
| | - Miao Sun
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Zhice Xu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China.,Center for Perinatal Biology, Loma Linda University, Loma Linda, California, USA
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Yaoita F, Muto M, Murakami H, Endo S, Kozawa M, Tsuchiya M, Tadano T, Tan-No K. Involvement of peripheral alpha2A adrenoceptor in the acceleration of gastrointestinal transit and abdominal visceral pain induced by intermittent deprivation of REM sleep. Physiol Behav 2018; 186:52-61. [DOI: 10.1016/j.physbeh.2018.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/11/2018] [Accepted: 01/11/2018] [Indexed: 02/06/2023]
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Yoshikawa Y, Hirata N, Kawaguchi R, Tokinaga Y, Yamakage M. Dexmedetomidine Maintains Its Direct Cardioprotective Effect Against Ischemia/Reperfusion Injury in Hypertensive Hypertrophied Myocardium. Anesth Analg 2018; 126:443-452. [DOI: 10.1213/ane.0000000000002452] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Gao Q, Tang J, Li N, Liu B, Zhang M, Sun M, Xu Z. What is precise pathophysiology in development of hypertension in pregnancy? Precision medicine requires precise physiology and pathophysiology. Drug Discov Today 2017; 23:286-299. [PMID: 29101000 DOI: 10.1016/j.drudis.2017.10.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/25/2017] [Accepted: 10/23/2017] [Indexed: 01/12/2023]
Abstract
It is widely accepted that placental ischemia is central in the evolution of hypertension in pregnancy. Many studies and reviews have targeted placental ischemia to explain mechanisms for initiating pregnancy hypertension. The placenta is rich in blood vessels, which are the basis for developing placental ischemia. However, is the physiology of placental vessels the same as that of nonplacental vessels? What is the pathophysiology of placental vessels in development of pregnancy hypertension? This review aims to provide a comprehensive summary of special features of placental vascular regulations and the pathophysiological changes linked to preeclamptic conditions. Interestingly, some popular theories or accepted concepts could be based on our limited knowledge and evidence regarding placental vascular physiology, pharmacology and pathophysiology. New views raised could offer interesting ideas for future investigation of mechanisms as well as targets for pregnancy hypertension.
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Affiliation(s)
- Qinqin Gao
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jiaqi Tang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Na Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Bailin Liu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Mengshu Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Miao Sun
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China.
| | - Zhice Xu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China; Center for Perinatal Biology, Loma Linda University, CA, USA.
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Berg T. β- and α 2-Adrenoceptor Control of Vascular Tension and Catecholamine Release in Female Normotensive and Spontaneously Hypertensive Rats. Front Neurol 2017; 8:130. [PMID: 28424658 PMCID: PMC5380753 DOI: 10.3389/fneur.2017.00130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 03/20/2017] [Indexed: 11/26/2022] Open
Abstract
As in humans, young, female, spontaneously hypertensive rats (SHR) have a lower blood pressure than male SHR. In male, normotensive rats (WKY), α2- and β1+2-adrenoceptors (AR) reciprocally controlled catecholamine release and vascular smooth muscle tension. This interaction was malfunctioning in male SHR. The present study analyzed if a favorable shift in the α2/β1+2AR interaction may represent an antihypertensive protection in females. Female SHR (early hypertension, 12–14 weeks) and age-matched WKY were infused with tyramine (15 min) to stimulate norepinephrine (NE) release through the reuptake transporter, consequently preventing reuptake. Presynaptic control of vesicular release was therefore reflected as differences in overflow to plasma. The released NE increased total peripheral vascular resistance (TPR). The results showed that β1>2AR facilitated tyramine-stimulated NE release in both strains, also in the presence of α2AR-antagonist (L-659,066). βAR-antagonist (atenolol-β1, ICI-118551-β2, nadolol-β1+2) had no effect on the increased secretion of epinephrine after L-659,066 in WKY, but β1>2AR-antagonist augmented the L-659,066-induced increase in the secretion of epinephrine in SHR. Nadolol increased the TPR response to tyramine with a greater effect in WKY than SHR, whereas β1or2-selective antagonists did not. One βAR-subtype may therefore substitute for the other. When both β1+2AR were blocked, α2AR-antagonist still reduced the TPR response in WKY but not SHR. Thus, α2/β1+2AR reciprocally controlled catecholamine release, with a particular negative β1AR-influence on α2AR-auto-inhibition of epinephrine secretion in SHR. Moreover, in these female rats, β1/2AR-independent α2AR-mediated vasoconstriction was seen in WKY but not SHR, but β1/2AR-mediated vasodilation downregulated adrenergic vasoconstriction, not only in WKY but also in SHR.
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Affiliation(s)
- Torill Berg
- Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Cobos-Puc LE, Sánchez-López A, Centurión D. Pharmacological analysis of the cardiac sympatho-inhibitory actions of moxonidine and agmatine in pithed spontaneously hypertensive rats. Eur J Pharmacol 2016; 791:25-36. [DOI: 10.1016/j.ejphar.2016.08.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 02/02/2023]
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