17ß-Estradiol protects against the effects of a high fat diet on cardiac glucose, lipid and nitric oxide metabolism in rats

Abstract

The aim of this study was to investigate the in vivo effects of estradiol (E2) on myocardial metabolism and inducible nitric oxide synthase (iNOS) expression/activity in obese rats. Male Wistar rats were fed with a normal or a high fat (HF) diet (42% fat) for 10 weeks. Half of the HF fed rats were treated with a single dose of E2 while the other half were placebo-treated. 24h after treatment animals were sacrificed. E2 reduced cardiac free fatty acid (FFA) (p<0.05), L-arginine (p<0.01), iNOS mRNA (p<0.01), and protein (p<0.05) levels and translocation of the FFA transporter (CD36) (p<0.01) to the plasma membrane (PM) in HF fed rats. In contrast, Akt phosphorylation at Thr308 (p<0.05) and translocation of the glucose transporter GLUT4 (p<0.05) to the PM increased after E2 tretment in HF rats. Our results indicate that E2 acts via PI3K/Akt signaling pathway to partially protect myocardial metabolism by attenuating the detrimental effects of increased iNOS expression/activity in HF fed rats.