Effects of acute and 2-Day genistein treatment on cardiac function and ischemic tolerance in ovariectomized rats

Genistein Induces Estrogen-Like Effects in Ovariectomized Rats but Fails to Increase Cardiac GLUT4 and Oxidative Stress

“…3 This study aimed to follow up on our previous work demonstrating that in OVX rats, 2 days of subcutaneous injections with genistein improved ischemic tolerance (i.e., contractility and cardiac output improved to *75% and *40% of the measured preischemic function). 23 In this study, the use of a more chronic application of genistein (2 weeks vs. 2 days) would better rep- …”

“…21,22 In addition, we recently demonstrated that genistein exerts an anti-ischemic effect in the hearts of OVX rats following a 2-day treatment period with the same concentration of genistein (250 mg=kg=day) and same route of administration (daily subcutaneous injections) as is used in the current study. 23 In view of the aforementioned previously reported protective effects of genistein on cardiovascular functions= systems, the purpose of this study was to better understand genistein's mechanism of action, more specifically in terms of its estrogen-like effects. We examined the effects of a 2-week treatment period of genistein (250 mg=kg=day) on physical and several physiological characteristics of OVX rats, measuring products of oxidative stress, cardiac GLUT4 protein expression, and various cardiovascular plasma markers.…”

“…37 The precise role of genistein on cardiac GLUT4 expression remains unclear, although we have demonstrated that an acute 2-day genistein treatment in OVX rats reduced cardiac GLUT4 levels. 23 Those data suggested that decreased GLUT4 levels could be related to the genistein-mediated ischemic tolerance. 23 In the present study, cardiac GLUT4 levels remained unchanged at the end of the 2-week genistein treatment.…”

“…23 Those data suggested that decreased GLUT4 levels could be related to the genistein-mediated ischemic tolerance. 23 In the present study, cardiac GLUT4 levels remained unchanged at the end of the 2-week genistein treatment. The reasons for these differences are not clear but may reflect the duration of the treatment period and consequently the amount of genistein metabolized.…”

“…However, this does not suggest that the oxidative stress capacity of genistein-treated hearts is limited because we recently reported that a 2-day treatment period increases tolerance of hearts to severe ischemia. 23 Cellular defenses against oxidative stress also include superoxide dismutase, catalase, and glutathione peroxidase, all of which are increased with either estrogen or genistein. 11,45,46 In conclusion, the results of this study demonstrate favorable effects of genistein on physical characteristics in the OVX rat, used here as a model for the postmenopausal condition.…”