1
|
Douglass A, Dattilo M, Feola AJ. Evidence for Menopause as a Sex-Specific Risk Factor for Glaucoma. Cell Mol Neurobiol 2023; 43:79-97. [PMID: 34981287 PMCID: PMC9250947 DOI: 10.1007/s10571-021-01179-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/03/2021] [Indexed: 01/07/2023]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by progressive loss of visual function and retinal ganglion cells (RGC). Current epidemiological, clinical, and basic science evidence suggest that estrogen plays a role in the aging of the optic nerve. Menopause, a major biological life event affecting all women, coincides with a decrease in circulating sex hormones, such as estrogen. While 59% of the glaucomatous population are females, sex is not considered a risk factor for developing glaucoma. In this review, we explore whether menopause is a sex-specific risk factor for glaucoma. First, we investigate how menopause is defined as a sex-specific risk factor for other pathologies, including cardiovascular disease, osteoarthritis, and bone health. Next, we discuss clinical evidence that highlights the potential role of menopause in glaucoma. We also highlight preclinical studies that demonstrate larger vision and RGC loss following surgical menopause and how estrogen is protective in models of RGC injury. Lastly, we explore how surgical menopause and estrogen signaling are related to risk factors associated with developing glaucoma (e.g., intraocular pressure, aqueous outflow resistance, and ocular biomechanics). We hypothesize that menopause potentially sets the stage to develop glaucoma and therefore is a sex-specific risk factor for this disease.
Collapse
Affiliation(s)
- Amber Douglass
- grid.484294.7Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA USA
| | - Michael Dattilo
- grid.189967.80000 0001 0941 6502Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, B2503, Clinic B Building, 1365B Clifton Road NE, Atlanta, GA 30322 USA ,grid.414026.50000 0004 0419 4084Department of Ophthalmology, Atlanta Veterans Affairs Medical Center, Atlanta, GA USA ,grid.213917.f0000 0001 2097 4943Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA USA
| | - Andrew J. Feola
- grid.484294.7Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA USA ,grid.189967.80000 0001 0941 6502Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, B2503, Clinic B Building, 1365B Clifton Road NE, Atlanta, GA 30322 USA ,grid.213917.f0000 0001 2097 4943Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA USA
| |
Collapse
|
2
|
Jósvai A, Török M, Hetthéssy J, Mátrai M, Monori-Kiss A, Makk J, Vezér M, Sára L, Szabó I, Székács B, Nádasy GL, Várbíró S. Additive damage in the thromboxane related vasoconstriction and bradykinin relaxation of intramural coronary resistance arterioles in a rodent model of andropausal hypertension. Heliyon 2022; 8:e11533. [PMID: 36406706 PMCID: PMC9667244 DOI: 10.1016/j.heliyon.2022.e11533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/17/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022] Open
Abstract
Hypertension and andropause both accelerate age–related vascular deterioration. We aimed to evaluate the effects of angiotensin-II induced hypertension and deficiency of testosterone combined regarding the resistance coronaries found intramurally. Four male groups were formed from the animals: control group (Co, n = 10); the group that underwenr orchidectomy (ORC, n = 13), those that received an infusion of angiotensin-II (AII, n = 10) and a grous that received AII infusion and were also surgically orchidectomized (AII + ORC, n = 8). AII and AII + ORC animals were infused with infusing angiotensin-II (100 ng/min/kg) using osmotic minipumps. Orchidectomy was perfomed in the ORC and the AII + ORC groupsto establish deficiency regarding testosterone. Following four weeks of treatment, pressure-arteriography was performed in vitro, and the tone induced by administration of thromboxane-agonist (U46619) and bradykinin during analysis of the intramural coronaries (well-known to be resistance arterioles) was studied. U46619-induced vasoconstriction poved to be significantly decreased in the ORC and AII + ORC groups when compared with Co and AII animals. In ORC and AII + ORC groups, the bradykinin-induced relaxation was also significantly reduced to a greater extent compared to Co and AII rats. Following orchidectomy, the vasocontraction and vasodilatation capacity of blood vessels is reduced. The effect of testosterone deficiency on constrictor tone and relaxation remains pronounced even in AII hypertension: testosterone deficiency further narrows adaptation range in the double noxa (AII + ORC) group. Our studies suggest that vascular changes caused by high blood pressure and testosterone deficiency together may significantly increase age-related cardiovascular risk.
Collapse
Affiliation(s)
- Attila Jósvai
- Doctoral School of Theoretical and Translational Medicine, Semmelweis University, Budapest, Hungary
- Department of Neurosurgery, Hungarian Defense Forces Medical Centre, Budapest, Hungary
| | - Marianna Török
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
- Workgroup of Science Management, Doctoral School, Semmelweis University, Budapest, Hungary
- Corresponding author.
| | - Judit Hetthéssy
- Workgroup of Science Management, Doctoral School, Semmelweis University, Budapest, Hungary
- Department of Orthopedics, Semmelweis University, Budapest, Hungary
| | - Máté Mátrai
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Anna Monori-Kiss
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Jennifer Makk
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Márton Vezér
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - Levente Sára
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - István Szabó
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - Béla Székács
- Department Internal Medicine, Department Section of Geriatrics, Szt Imre Teaching Hospital, Budapest, Hungary
| | - György L. Nádasy
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Szabolcs Várbíró
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
- Workgroup of Science Management, Doctoral School, Semmelweis University, Budapest, Hungary
| |
Collapse
|
3
|
Jósvai A, Török M, Mátrai M, Hetthéssy J, Monori-Kiss A, Makk J, Székács B, Nádasy GL, Várbíró S. Effects of Testosterone Deficiency and Angiotensin II-Induced Hypertension on the Biomechanics of Intramural Coronary Arteries. J Sex Med 2020; 17:2322-2330. [PMID: 33067160 DOI: 10.1016/j.jsxm.2020.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/14/2020] [Accepted: 09/12/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Andropause and hypertension also increase the risk of coronary artery damage. AIM To investigate the effect of testosterone deficiency and hypertension on intramural coronary vessels. METHODS 4 groups of 8-week-old Sprague-Dawley rats were studied: control male (Co, n=10), orchidectomized male (OCT, n=13), angiotensin (AII) hypertensive male (AII, n=10), and AII hypertensive and OCT (AII + OCT, n=8). Surgical orchidectomy was performed, and an osmotic minipump was inserted for chronic angiotensin II infusion (100 ng/min/kg). After 4 weeks, spontaneous tone and biomechanical properties of the intramural coronary resistance artery were investigated in vitro, by pressure microarteriography. OUTCOMES Morphology and biomechanics of the intramural coronaries were evaluated: the outer diameter, wall thickness-to-lumen diameter ratio, and tangential wall stress in the contracted and relaxed states. RESULTS The outer diameter was reduced in OCT and AII + OCT groups (on 50 mmHg 315 ± 20 Co; 237 ± 21 OCT; 291 ± 16 AII, and 166 ± 12 μm AII + OCT). The increased wall thickness-to-lumen diameter ratio resulted in lower tangential wall stress in AII + OCT rats (on 50 mmHg 19 ± 2 Co; 24 ± OCT; 26 ± 5 AII, and 9 ± 1 kPa AII + OCT). Spontaneous tone was increased in the hypertensive rats (AII and AII + OCT groups) (on 50 mmHg 7.7 ± 1.8 Co; 6.1 ± 1.4 OCT; 14.5 ± 3.0 AII, and 17.4 ± 4.1 % AII + OCT). CLINICAL IMPLICATIONS Andropause alone can be considered as a cardiovascular risk factor that will further exacerbate vascular damage in hypertension. STRENGTHS & LIMITATIONS A limitation of our study is that it was performed on relatively young rats, and the conclusions might not apply to coronary remodelling in older animals with slower adaptation processes. CONCLUSIONS Testosterone deficiency and hypertension damage the mechanical adaptation of the vessel wall additively: double noxa caused inward eutrophic remodeling and increased tone. Jósvai A, Török M, Mátrai M, et al. Effects of Testosterone Deficiency and Angiotensin II-Induced Hypertension on the Biomechanics of Intramural Coronary Arteries. J Sex Med 2020;17:2322-2330.
Collapse
Affiliation(s)
- Attila Jósvai
- Department of Neurosurgery, Hungarian Defence Forces Medical Centre, Budapest, Hungary.
| | - Marianna Török
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - Máté Mátrai
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary
| | - Judit Hetthéssy
- Department of Orthopedics, Semmelweis University, Budapest, Hungary
| | - Anna Monori-Kiss
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary
| | - Jennifer Makk
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary
| | - Béla Székács
- 2nd Department Internal Medicine, Department Section of Geriatrics, Szt Imre Teaching Hospital, Budapest, Hungary
| | - György L Nádasy
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Szabolcs Várbíró
- Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
4
|
Monori-Kiss A, Antal P, Szekeres M, Varbiro S, Fees A, Szekacs B, Nadasy GL. Morphological remodeling of the intramural coronary resistance artery network geometry in chronically Angiotensin II infused hypertensive female rats. Heliyon 2020; 6:e03807. [PMID: 32368650 PMCID: PMC7184174 DOI: 10.1016/j.heliyon.2020.e03807] [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] [Received: 09/13/2019] [Revised: 03/03/2020] [Accepted: 04/16/2020] [Indexed: 11/30/2022] Open
Abstract
Segmental remodeling of resistance arteries, inhibition of angiogenetic processes, their rarefaction by AngiotensinII and hypertension are accepted facts. Less is known about alterations in resistance artery network geometry potentially induced by them. Female rats were infused with 100 ng/kg/min AngiotensinII with osmotic minipumps for four weeks that raised mean arterial blood pressure from 98 ± 3 to 125 ± 7 mmHg. Geometry of the left coronary artery system was studied on plastic casts and on in situ microsurgically prepared, saline infused video-microscoped networks (n = 13 and 11 controls and hypertensives, respectively). Parallel running branches, broken course of larger branches, multiple branchings and branch crossings have been identified (13 and 74 such deformities, in control and hypertensive networks, respectively, p < 0.01). Bifurcation angles increased with increasing asymmetry of daughter branches but not in hypertensives. Dividing the whole network (theoretically) into several hundreds of 50μm long ring units, ring frequency peaked at 200μm diameter in normal networks. This peak diminished and was replaced by a peak at 300μm in hypertensives (p < 0.01). In controls, diameter of vascular units decreased at a fairly even rate with flow distance from the orifice. The 350, 200, 150μm diameter units were found with highest frequencies at flow distances around 2.5, 5.5 and 7.5mm, respectively. This regular pattern disintegrated in hypertensives. Higher blood flow routes were needed to cover the same distance from the orifice (p < 0.01). Shrinkage and diminishment of many parallel connected 200μm segments, concomitant enlargement of many larger segments accompanied with morphological deformities can be expected to contribute to elevated vascular resistance.
Collapse
Affiliation(s)
- Anna Monori-Kiss
- Institute of Translational Medicine, Semmelweis University, 37-47 Tuzolto Str, H-1094, Budapest, Hungary
| | - Peter Antal
- Institute of Translational Medicine, Semmelweis University, 37-47 Tuzolto Str, H-1094, Budapest, Hungary
| | - Maria Szekeres
- Department of Physiology, Semmelweis University, 37-47 Tuzolto Str, H-1094, Budapest, Hungary.,Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, 17 Vas Str, H-1088, Budapest, Hungary
| | - Szabolcs Varbiro
- Department of Obstetrics and Gynecology, Semmelweis University, 78a Ulloi Str, H-1082, Budapest, Hungary
| | - Alexander Fees
- Department of Physiology, Semmelweis University, 37-47 Tuzolto Str, H-1094, Budapest, Hungary
| | - Bela Szekacs
- II. Department of Internal Medicine, Section of Geriatrics, Semmelweis University, 20-22 Halmi Str, H-1115, Budapest, Hungary
| | - Gyorgy L Nadasy
- Department of Physiology, Semmelweis University, 37-47 Tuzolto Str, H-1094, Budapest, Hungary
| |
Collapse
|
5
|
Management of intracranial haemorrhage, unruptured aneurysms and arteriovenous malformations during and after pregnancy. Curr Opin Neurol 2019; 32:36-42. [DOI: 10.1097/wco.0000000000000643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
6
|
Estrogen therapy may counterbalance eutrophic remodeling of coronary arteries and increase bradykinin relaxation in a rat model of menopausal hypertension. Menopause 2018; 23:778-83. [PMID: 27187011 PMCID: PMC4927223 DOI: 10.1097/gme.0000000000000654] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Objective: Hypertension causes adverse remodeling and vasomotor alterations in coronaries. Hormones such as estrogen may help counterbalance some of these effects. The aim of this study was to analyze the effects of ovariectomy and estrogen therapy in a rat model of menopausal hypertension induced by angiotensin II (AII). Methods: We investigated diameter, tone, and mechanics of intramural coronaries taken from ovariectomized female rats (n = 11) that received chronic AII treatment to induce hypertension, and compared the results with those found in female rats that were also given estrogen therapy (n = 11). The “hypertensive control” group (n = 11) underwent an abdominal sham operation, and received AII. After 4 weeks of AII treatment, side branches of left anterior descendent coronary (approximately 200 μm in diameter) were isolated, cannulated with plastic microcannulas at both ends, and studied in vitro in a vessel chamber. The inner and outer diameter of the arteries were measured by microangiometry, and spontenuous tone, wall thickness, wall cross-sectional area, tangential stress, incremental distensibility, circumferential incremental elastic modulus, thromboxane agonist-induced tone, and bradykinin-induced dilation were calculated. Results: In hypertension, intramural small coronaries show inward eutrophic remodeling after ovariectomy comparing with hypertensive controls. Estrogen therapy had an opposite effect on vessel diameter. Hormone therapy led to an increase in spontaneous tone, allowing for greater dilatative capacity. Conclusions: Estrogen may therefore be considered to counterbalance some of the adverse changes seen in the wall of intramural coronaries in the early stages of chronic hypertension.
Collapse
|
7
|
Endlich PW, Claudio ERG, Lima LCF, Ribeiro Júnior RF, Peluso AAB, Stefanon I, Bissoli NS, Lemos VS, Santos RASD, Abreu GRD. Exercise modulates the aortic renin-angiotensin system independently of estrogen therapy in ovariectomized hypertensive rats. Peptides 2017; 87:41-49. [PMID: 27884622 DOI: 10.1016/j.peptides.2016.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 01/08/2023]
Abstract
The renin-angiotensin-system is an important component of cardiovascular control and is up-regulated under various conditions, including hypertension and menopause. The aim of this study was to evaluate the effects of swimming training and estrogen therapy (ET) on angiotensin-II (ANG II)-induced vasoconstriction and angiotensin-(1-7) [ANG-(1-7)]-induced vasorelaxation in aortic rings from ovariectomized spontaneously hypertensive rats. Animals were divided into Sham (SH), Ovariectomized (OVX), Ovariectomized treated with E2 (OE2), Ovariectomized plus swimming (OSW) and Ovariectomized treated with E2 plus swimming (OE2+SW) groups. ET entailed the administration of 5μg of 17β-Estradiol three times per week. Swimming was undertaken for sixty minutes each day, five times per week. Both, training and ET were initiated seven days following ovariectomy. Forty-eight hours after the last treatment or training session, the animals' systolic blood pressures were measured, and blood samples were collected to measure plasma ANG II and ANG-(1-7) levels via radioimmunoassay. In aortic rings, the vascular reactivity to ANG II and ANG-(1-7) was assessed. Expression of ANG-(1-7) in aortic wall was analyzed by immunohistochemistry. The results showed that both exercise and ET increased plasma ANG II levels despite attenuating systolic blood pressure. Ovariectomy increased constrictor responses to ANG II and decreased dilatory responses to ANG-(1-7), which were reversed by swimming independently of ET. Moreover, it was observed an apparent increase in ANG-(1-7) content in the aorta of the groups subjected to training and ET. Exercise training may play a cardioprotective role independently of ET and may be an alternative to ET in hypertensive postmenopausal women.
Collapse
Affiliation(s)
- Patrick W Endlich
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil; Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Federal University of Valleys of Jequitinhonha and Mucuri, Teófilo Otoni, MG, Brazil
| | - Erick R G Claudio
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil
| | - Leandro C F Lima
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Rogério F Ribeiro Júnior
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil
| | - Antonio A B Peluso
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ivanita Stefanon
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil
| | - Nazaré S Bissoli
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil
| | - Virginia S Lemos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Robson A S Dos Santos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Glaucia R de Abreu
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitoria, ES, Brazil.
| |
Collapse
|
8
|
Depressed calcium cycling contributes to lower ischemia tolerance in hearts of estrogen-deficient rats. Menopause 2016; 22:773-82. [PMID: 25513985 DOI: 10.1097/gme.0000000000000377] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Estrogens enhance ischemia tolerance (IT) in the myocardium, the mechanism of which remains unclear. We investigated the effects of long-term estrogen deprivation on the intracellular calcium (Ca(2+)(i)) transient of the heart and its possible influence on IT. METHODS Hearts of ovariectomized (OVX) and sham-operated (control) adult female rats (some receiving estrogen therapy) were studied 10 weeks after surgical operation: control (n = 8), OVX (n = 10), sham-operated estrogen-substituted (n = 7), and ovariectomized estrogen-substituted (n = 9). In vivo heart function was assessed by echocardiography, whereas Ca(2+)(i) transients were recorded, concomitantly with left ventricular pressure and coronary flow, by Indo-1 surface fluorometry in isolated Langendorff-perfused hearts. Isolated hearts were subjected to a 30-minute global ischemia-30-minute reperfusion protocol. Left ventricular expression of myocardial sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA2a), phospholamban (PLB), and Ser16-phosphorylated PLB was measured. RESULTS Ovariectomy did not influence resting cardiac function in vivo or ex vivo. However, Ca(2+) removal was slower. During ischemia, Ca(2+)(i) elevation and ischemic contracture were more pronounced after ovariectomy. Postischemic restitution of inotropic function (developed pressure; +dP/dt(max)) and lusitropic function (-dP/dt(max)) and Ca(2+)(i) transient recovery (amplitude; ±dCa(2+)(i)/dt(max)) were decreased in OVX hearts. Sarcoendoplasmic reticulum Ca(2+)-ATPase expression was unaltered, whereas PLB and Ser16-phosphorylated PLB levels were higher after ovariectomy. All effects of ovariectomy were restored by estrogen therapy. CONCLUSIONS Ovariectomy impairs myocardial Ca(2+) removal by increasing the expression of the SERCA2a inhibitor PLB. Defective Ca(2+) transport causes ischemic Ca(2+)(i) overload and insufficient postischemic recovery of Ca(2+)(i) transients, which entail depressed hemodynamic restitution. Protection of intact Ca(2+) cycling in the myocardium by estrogens plays a major role in enhancing IT.
Collapse
|
9
|
Mátrai M, Hetthéssy J, Nádasy GL, Monos E, Székács B, Várbíró S. Sex differences in the biomechanics and contractility of intramural coronary arteries in angiotensin II-induced hypertension. ACTA ACUST UNITED AC 2013; 9:548-56. [PMID: 23217570 DOI: 10.1016/j.genm.2012.10.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 10/12/2012] [Accepted: 10/15/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND It is well known that sex differences occur in both the pathogenesis and therapy of hypertension. A deeper understanding of the underlying processes may be helpful when planning a personalized therapeutic strategy. OBJECTIVE In laboratory animal experiments, we studied the early mechanisms of vascular adaptation of the intramural small coronary arteries that play a fundamental role in the blood supply of the heart. METHODS In our study, an osmotic minipump was implanted into 10 male and 10 female Sprague-Dawley rats. The pump remained in situ for 4 weeks, infusing a dose of 100 ng/kg/min angiotensin II acetate. Four weeks later, the animals were killed, and the intramural coronary arteries from the left coronary branch, which are fundamentally responsible for the blood supply of the heart, were prepared. The pharmacologic reactivity and biomechanical properties of the prepared segments were studied in a tissue bath. RESULTS The relative heart mass and vessel wall thickness were greater in females than males (0.387 [0.009] g/100 g vs 0.306 [0.006] g/100 g body weight; 41.9 [4.09] μm vs 33.45 [3.37] μm on 50 mm Hg). The vessel tone and vasoconstriction in response to thromboxane agonists were, however, significantly more pronounced in males. The extent of relaxation in response to bradykinin was also greater in females. Although we observed inward eutrophic remodeling in females, an increase in wall stress and elastic modulus dominated in males. CONCLUSION The early steps of angiotensin II-dependent hypertension evoked very different adaptation mechanisms in males and females.
Collapse
Affiliation(s)
- Máté Mátrai
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Faculty of Medicine, Budapest, Hungary.
| | | | | | | | | | | |
Collapse
|
10
|
Sara L, Nadasy GL, Antal P, Monori-Kiss A, Szekeres M, Masszi G, Monos E, Varbiro S. Pharmacological reactivity of resistance vessels in a rat PCOS model - vascular effects of parallel vitamin D₃ treatment. Gynecol Endocrinol 2012; 28:961-4. [PMID: 22621463 DOI: 10.3109/09513590.2012.683079] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of this study was to clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on pharmacological reactivity of a resistance vessel in a rat model and the possible modulatory role of 1,25-(OH)₂-cholecalciferol (vitamin D₃). The PCOS model was induced in adolescent female Wistar rats by a 10-week DHT treatment. Norepinephrine induced contractility and acetylcholine relaxation were tested in arterioles by pressure arteriography in control as well as DHT- and DHT plus vitamin D₃-treated (DHT+D3) animals. Decreased vasoconstriction and dilatation were detected after DHT treatment. Concomitant vitamin D₃ treatment increased the contractile response and resulted in more relaxed vessels. Endothelial dilation tested with acetylcholine was lower after DHT treatment, this effect was not depend on vitamin D₃ supplementation. In conclusion, hyperandrogenic state resulted in reduced endothelium- and smooth muscle-dependent vasorelaxation and constriction with a complete loss of nitric oxide (NO)-dependent relaxation compared with controls. These alterations caused by chronic DHT treatment were partially reversed by concomitant vitamin D₃ administration.
Collapse
MESH Headings
- Animals
- Arterioles/drug effects
- Arterioles/physiopathology
- Cardiovascular Agents/administration & dosage
- Cardiovascular Agents/therapeutic use
- Cardiovascular Diseases/etiology
- Cardiovascular Diseases/prevention & control
- Cholecalciferol/administration & dosage
- Cholecalciferol/therapeutic use
- Dihydrotestosterone
- Disease Models, Animal
- Drug Implants
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiopathology
- Female
- Injections, Subcutaneous
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiopathology
- Polycystic Ovary Syndrome/drug therapy
- Polycystic Ovary Syndrome/physiopathology
- Rats
- Rats, Wistar
- Thigh
- Vascular Resistance/drug effects
- Vasoconstriction/drug effects
- Vasodilation/drug effects
Collapse
Affiliation(s)
- Levente Sara
- Second Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Sára L, Nádasy G, Antal P, Szekeres M, Monori-Kiss A, Horváth EM, Tőkés AM, Masszi G, Monos E, Várbíró S. Arteriolar biomechanics in a rat polycystic ovary syndrome model - effects of parallel vitamin D3 treatment. ACTA ACUST UNITED AC 2012; 99:279-88. [PMID: 22982716 DOI: 10.1556/aphysiol.99.2012.3.5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
UNLABELLED To clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on arteriolar biomechanics in a rat model and the possible modulatory role of vitamin D3. METHODS AND RESULTS The PCOS model was induced in female Wistar rats by ten-weeks DHT treatment. Arteriolar biomechanics was tested in arterioles by pressure arteriography in control as well as DHT- and DHT with vitamin D3-treated animals in contracted and passive conditions. Increased wall stress and distensibility as well as increased vascular lumen were detected after DHT treatment. Concomitant vitamin D3 treatment lowered the mechanical load of the arterioles and restored the vascular diameter. CONCLUSION The hyperandrogenic state resulted in more rigid, less flexible arteriolar walls with increased vascular lumen compared with controls. DHT treatment caused eutrophic remodelling of gracilis arteriole. These prehypertensive alterations caused by chronic DHT treatment were mostly reversed by concomitant vitamin D3 administration.
Collapse
Affiliation(s)
- L Sára
- 2nd Department Obstet. Gynecol, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Szekeres M, Nádasy GL, Turu G, Soltész-Katona E, Tóth ZE, Balla A, Catt KJ, Hunyady L. Angiotensin II induces vascular endocannabinoid release, which attenuates its vasoconstrictor effect via CB1 cannabinoid receptors. J Biol Chem 2012; 287:31540-50. [PMID: 22787147 DOI: 10.1074/jbc.m112.346296] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the vascular system angiotensin II (Ang II) causes vasoconstriction via the activation of type 1 angiotensin receptors. Earlier reports have shown that in cellular expression systems diacylglycerol produced during type 1 angiotensin receptor signaling can be converted to 2-arachidonoylglycerol, an important endocannabinoid. Because activation of CB(1) cannabinoid receptors (CB(1)R) induces vasodilation and reduces blood pressure, we have tested the hypothesis that Ang II-induced 2-arachidonoylglycerol release can modulate its vasoconstrictor action in vascular tissue. Rat and mouse skeletal muscle arterioles and mouse saphenous arteries were isolated, pressurized, and subjected to microangiometry. Vascular expression of CB(1)R was demonstrated using Western blot and RT-PCR. In accordance with the functional relevance of these receptors WIN55212, a CB(1)R agonist, caused vasodilation, which was absent in CB(1)R knock-out mice. Inhibition of CB(1)Rs using O2050, a neutral antagonist, enhanced the vasoconstrictor effect of Ang II in wild type but not in CB(1)R knock-out mice. Inverse agonists of CB(1)R (SR141716 and AM251) and inhibition of diacylglycerol lipase using tetrahydrolipstatin also augmented the Ang II-induced vasoconstriction, suggesting that endocannabinoid release modulates this process via CB(1)R activation. This effect was independent of nitric-oxide synthase activity and endothelial function. These data demonstrate that Ang II stimulates vascular endocannabinoid formation, which attenuates its vasoconstrictor effect, suggesting that endocannabinoid release from the vascular wall and CB(1)R activation reduces the vasoconstrictor and hypertensive effects of Ang II.
Collapse
Affiliation(s)
- Mária Szekeres
- Department of Physiology, Semmelweis University, H-1444 Budapest, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Matrai M, Szekacs B, Mericli M, Nadasy G, Szekeres M, Banhidy F, Bekesi G, Monos E, Várbíró S. Biomechanics and vasoreactivity of female intramural coronaries in angiotensin II induced hypertension. ACTA ACUST UNITED AC 2010; 97:31-40. [DOI: 10.1556/aphysiol.97.2010.1.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
14
|
Jamous MA, Nagahiro S, Kitazato KT, Satomi J, Satoh K. Role of estrogen deficiency in the formation and progression of cerebral aneurysms. Part I: experimental study of the effect of oophorectomy in rats. J Neurosurg 2005; 103:1046-51. [PMID: 16381191 DOI: 10.3171/jns.2005.103.6.1046] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. Estrogen has been shown to play a central role in vascular biology. Although it may exert beneficial vascular effects, its role in the pathogenesis of cerebral aneurysms remains to be determined. To elucidate the role of hormones further, the authors examined the effects of bilateral oophorectomy on the formation and progression of cerebral aneurysms in rats.
Methods. Forty-five female, 7-week-old Sprague—Dawley rats were divided into three equal groups. Group I consisted of intact rats (controls). To induce cerebral aneurysms, the animals in Groups II and III were subjected to ligation of the right common carotid and bilateral posterior renal arteries. One month later, the rats in Group II underwent bilateral oophorectomy. Three months after the experiment began all animals were killed and cerebral vascular corrosion casts were prepared and screened for cerebral aneurysms by using a scanning electron microscope. Plasma was used to determine the level of estradiol and the gelatinase activity.
Hypertension developed in all rats except those in the control group. The estradiol level was significantly lower in Group II than in the other groups (p < 0.01). The incidence of cerebral aneurysm formation in Group II (60%) was three times higher than that in Group III (20%), and the mean size of aneurysms in Group II (76 ± 27 µm, mean ± standard deviation) was larger than that in Group III (28 ± 4.6 µm) (p < 0.05). No aneurysm developed in control animals (Group I), and there was no significant difference in plasma gelatinase activity among the three groups.
Conclusions. The cerebral aneurysm model was highly reproducible in rats. Bilateral oophorectomy increased the susceptibility of rats to aneurysm formation, indicating that hormones play a role in the pathogenesis of cerebral aneurysms.
Collapse
Affiliation(s)
- Mohammad A Jamous
- Department of Neurosurgery, School of Medicine, University of Tokushima, Tokushima City, Japan
| | | | | | | | | |
Collapse
|
15
|
Abstract
Hypertension, particularly systolic hypertension, affects postmenopausal women and is an important risk factor for cardiovascular disease in this group. In the last year, several papers have better defined the mechanisms by which hormone replacement therapy influences blood pressure in postmenopausal women, including effects on nitric oxide, angiotensin II and vascular stiffness (compliance). Currently, data concerning the influence of hormone replacement therapy on blood pressure in postmenopausal women are inconclusive because of the limitations of published studies. It is clear, however, that hypertension is not a contraindication to starting hormone replacement therapy.
Collapse
Affiliation(s)
- Veronica Franco
- Vascular Biology and Hypertension Program, Cardiovascular Diseases, University of Alabama at Birmingham, Alabama, USA
| | | |
Collapse
|
16
|
Várbíró S, Vajó Z, Nádasy GL, Monos E, Acs N, Lóránt M, Felicetta JV, Székacs B. Sex hormone replacement therapy reverses altered venous contractility in rats after pharmacological ovariectomy. Menopause 2002; 9:122-6. [PMID: 11875331 DOI: 10.1097/00042192-200203000-00007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Female sex hormones have several important effects on the venous system. We earlier found that hormone replacement has a significant effect on venous distensibility, but effects of menopause and hormone replacement on venous contractility have never been studied. Therefore, and because the changes we found earlier in distensibility were most likely caused by alterations of contractility, we examined the changes in contractility of saphenous vein caused by depletion and replacement of sex hormones in female rats. DESIGN Twenty Sprague-Dawley rats were pharmacologically ovariectomized by triptorelin. Ten of these rats received combined sex hormone replacement (HRT) with estradiol propionate and medroxyprogesterone acetate. The rest were given vehicle. Ten animals without ovariectomy served as controls. After 3 months of treatment, segments of the saphenous vein were dissected. Pressure-diameter curves were recorded in relaxed, contracted, and control states. RESULTS Venous diameter, adjusted for body weight, was significantly decreased after pharmacological ovariectomy. HRT increased the diameter. The presence of sex hormones augmented norepinephrine contraction measured at physiological pressures (control: 19.2 +/- 2.3%; pharmacological ovariectomy: 15.2 +/- 1.4%, p < 0.05 and 17.8 +/- 2.2% following HRT). Myogenic (spontaneous) tone of the saphenous vein did not change after ovariectomy, but it was lowered by hormone replacement (control: 8 +/- 1.1%; ovariectomy: 6.9 +/- 2.5%; ovariectomy + HRT: 2.7 +/- 1.1%, p < 0.05). CONCLUSIONS Sex hormone depletion induces significant alterations in contractility of the saphenous vein, which could perturb venous capacitance function and distensibility. This effect has a potential role in the development of hypertension and venous varicosity, and these changes could possibly be prevented by HRT.
Collapse
Affiliation(s)
- Szabolcs Várbíró
- Second Department of Obstetrics and Gynecology, Semmelweis University, Faculty of Medicine, Budapest, Hungary
| | | | | | | | | | | | | | | |
Collapse
|