COMPARATIVE EFFECTS OF EARLY AND PHYSIOLOGICAL OVARIAN HORMONES DEPRIVATION ON CORONARY BED REACTIVITY AND CARDIAC CONTRATILITY IN SPONTANEOUSLY HYPERTENSIVE RATS - ROLE OF AGING

• Grant number: 23/08051-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2023
• End date: September 30, 2025
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Hugo Celso Dutra de Souza
• Grantee: João Vitor Martins Bernal da Silva
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Introduction: Systemic arterial hypertension (SAH) is accompanied by a reduction in the cardiac contractile capacity and alterations in the reactivity of the coronary bed. However, in women of reproductive age, this condition may be less severe due to the cardiovascular protection exerted by ovarian hormones. In turn, physiological ovarian failure (menopause) represents a watershed in this protection, which favors the development of more severe morphological and functional heart changes that can progress to more severe heart failure, especially in hypertensive women. However, we still do not know the contribution of aging in this process. In this case, another condition called early ovarian failure that affects a portion of women can help answer this question. Objective: To investigate in spontaneously hypertensive rats (SHR) whether early ovarian failure results in more severe morphological and functional impairments when compared with physiological ovarian failure, or whether aging is a condition that prevails over morphological and functional impairments, in particular the coronary bed reactivity and cardiac contractility. Methods: 64 animals divided into two large groups will be used; group of Wistar Kyoto rats (WK; N=32) and group of spontaneously hypertensive rats (SHR; N=32). Half of each group will undergo ovarian hormone deprivation through ovariectomy (N=16) or SHAM surgery (N=16) at the 24th week of life, while the other half will undergo ovarian hormone deprivation through ovariectomy or SHAM surgery at the 60th week of life. All animals will be evaluated at the 72nd week of life using the following protocols; recording of blood pressure and heart rate through plethysmography to be performed at the 24th, 36th, 48th, 60th and 72nd weeks of life; cardiac morphofunctional assessment through two-dimensional echocardiography at the 24th, 72nd weeks; analysis of coronary bed reactivity and left ventricular contractility in an isolated heart by means of increased flow and administration of beta-adrenergic agonists, dobutamine (0.5 - 50 nmol) and salbutamol (1 - 100 nmol); quantification of the expression of cardiac beta-adrenergic receptors; and cardiac histological analysis.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BERNAL, JOAO VITOR MARTINS; DA VEIGA, ANA CATARINE; PHILBOIS, STELLA VIEIRA; RIBEIRO, VICTOR BARBOSA; AGUILAR, BRUNO AUGUSTO; PAIXAO, TALLYS EDUARDO VELASCO; CHINELLATO, NAIARA; SANCHEZ-DELGADO, JUAN CARLOS; GASTALDI, ADA CLARICE; DE SOUZA, HUGO CELSO DUTRA. Women With Polycystic Ovary Syndrome and Excess Body Fat Exhibit Atypical Sympathetic Autonomic Modulation That is Partially Reversed by Aerobic Physical Training. CLINICAL ENDOCRINOLOGY, v. N/A, p. 12-pg., 2024-11-11. (22/02006-5, 23/08051-5)

J.V.M. BERNAL; J.C. SÁNCHEZ-DELGADO; A.M. JÁCOME-HORTÚA; A.C. VEIGA; G.V. ANDRADE; M.R. RODRIGUES; H.C.D. DE SOUZA. Effects of physical exercise on the lipid profile of perimenopausal and postmenopausal women: a systematic review and meta-analysis. Brazilian Journal of Medical and Biological Research, v. 58, 2025-03-03. (23/08051-5)