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

The aim of this study was to investigate the in vivo effects of 17 beta-estradiol (E-2) 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 E-2 while the other half were placebo-treated. 24 h after treatment animals were sacrificed. E-2 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 E-2 treatment in HF rats. Our results indicate that E-2 acts via the PI3K/Akt signalling pathway to partially protect myocardial metabolism by attenuating the detrimental effects of increased iNOS expression/activity in HF fed rats. (C) 2017 Elsevier B.V. All rights reserved.