Age‐Related Changes Heart Function in the Female SHR, a Model of Postmenopausal Cardiovascular Physiology (LB712)

Abstract

Age‐Related Changes Heart Function in the Female SHR, a Model of Postmenopausal Cardiovascular Physiology. Joseph McCarthy1, Rolando J.J. Ramirez1, Jacqueline Novak2. 1Biology, The University of Akron, Akron, OH, 2Department of Math and Sciences, Walsh University, N. Canton, OH.Women have a decreased risk of cardiovascular disease compared to men until after menopause when the risk is similar between men and women. The mechanism for cardioprotective effect is unclear. In order to study the physiological changes which occur in the cardiovascular system of women after menopause, it is necessary to identify animal models. One model of post‐menopausal physiology is the aged spontaneously hypertensive female rats (SHR). The endocrine and blood pressure changes have been previously recorded by Reckelhoff and colleagues; however, the cardiac function has not been examined via isolated heart techniques. The purpose of this study was to compare the contractility of hearts isolated from postmenopausal rats (aged SHR females) compared to young SHR controls. . Hearts studied using an isolated Langendorff system. The contractility measurements were recorded at 3 different ventricular volumes (0.05, 0.10, and 0.15ml) using a pressure transducer and the data were collected using WinDaq (DI‐720‐Di‐7x0). Contractility was calculated by the change in pressure over the change in time(dP/dt). A significant increase in contractility was shown between the young and old SHR models at the three different volumes. For example, at 0.15ml, the contractility was 6.19 1.49 in the post‐menopausal rats compared to 4.03 0.91 in the young SHR. These results indicate that there are significant age‐related changes in the isolated heart of aged SHR which is further evidence that this is an important model for studying post‐menopausal changes in heart function.Grant Funding Source: Supported by NIH 1R15HL097343‐01A2