Influência do exercício físico no remodelamento cardíaco de ratos espontaneamente hipertensos

• Autor(a) principal: Pagan, Luana Urbano [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/123179; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/06-05-2015/000825542.pdf
• topic: Hipertensão - Tratamento; Exercícios físicos - Uso terapêutico; Insuficiencia cardiaca; Rato como animal de laboratorio; Hypertension

Introduction: The systemic arterial hypertension (SAH) is a highly prevalent disease worldwide. SAH induces cardiac alterations characterized by left ventricular (LV) hypertrophy, ventricular diastolic and / or systolic dysfunction and clinical manifestations such as arrhythmia and heart failure (HF). The process by which chronic hemodynamic overload, such as hypertension, induces these alterations is known as cardiac remodeling. Within this process, changes in interstitial collagen matrix play a fundamental role. The pressure overload caused by hypertension may lead to changes in collagen architecture increasing myocardial fibrosis and stiffness, with consequent LV diastolic dysfunction. Physical exercise has shown benefit as coadjuvant measure in the treatment of HF, but its effect on cardiac remodeling, particularly associated with uncontrolled hypertension, remains unclear. Therefore, the aim of this study was to evaluate the influence of physical training on cardiac remodeling in spontaneously hypertensive rats (SHR) during the development of HF. Methods: Four experimental groups were constituted as follows: male SHR, 16 month old, sedentary (SHR-SED, n=25); exercised male SHR (SHR-EX, n=25), sedentary control male rats Wistar-Kyoto (WKY-SED, n=17); and exercised male WKY (WKYEX, n=18). Animals from the exercised groups were submitted to a treadmill exercise protocol, five days a week, for four months. The in vivo cardiac structural and functional evaluation was performed by echocardiography. The in vitro myocardial function was evaluated by isolated left ventricular papillary muscle preparations. LV tissue samples were obtained for quantification of hydroxyproline concentration, histological analysis and quantification of interstitial collagen soluble and insoluble fractions. Genic expression of collagen types I and III and lysyl oxidase was assessed by real time RT-PCR. Comparisons between ...