Effects of sex hormones on myocardial infarction size and left ventricular myocardial contractility and relaxation in rats / 中国病理生理杂志

ABSTRACT

Effects of sex hormones on infarction size(IS) and left ventricular myocardial contractility and relaxation (LVMC, LVMR) in rats after left coronary occlusion in order to make a model of myocardial infarction(MI) were studied. Male adult rats were randomly divided into 3 groups, and pre-treated respectively with testosterone propionate(10mg/kg), oestradioli benzoatis(500?g/kg), or vehicle (0.sml/kg) for 3 weeks (3 times per week) before MI. The injection was continued after MI, on 9th of MI indexes of LVMC and LVMR, IS and the levels of sex hormones were measured. The results showed that (1) IS were nor affected by both testosterone and oestradiol. (2) Indexes of LVMC and LVMR, i. e. dp/dtmax, LVSP and -dp/dtmax, were lightly inhibited by hyperoestrogencmia(HE), the increasing rate of body weight (IRBW) before and after MI were significantly inhibited by HE. However, indexes of LVMC and LVMR were significantly improved by hypertestosteronemia(HT), but IRBW were not affected by HT. (3) It is interested to note that there was a significant positve correlation between the level of plasma testosterone and indexes of LVMC and LVMR, and an inversive correlation between the level of oestradiol and indexes of LVMC and LVMR, suggesting sex hormones really pay a rolein the pathophysiological process of MI.