Effects of 17β-estradiol on cardiac Na(+)/K(+)-ATPase in high fat diet fed rats.
The aim of this study was to investigate in vivo effects of estradiol on Na(+)/K(+)-ATPase activity/expression in high fat (HF) diet fed rats. Adult male Wistar rats were fed normally (Control, n = 7) or with a HF diet (Obese, n = 14) for 10 weeks. After 10 weeks, half of the obese rats were treated with estradiol (Obese + Estradiol, n = 7, 40 μg/kg, i.p.) as a bolus injection and 24 h after treatment all the rats were sacrificed. Estradiol in vivo in obese rats in comparison with obese non-treated rats led to a statistically significant increase in concentration of serum Na(+) (p < 0.05), Na(+)/K(+)-ATPase activity (p < 0.01), expression of α1 (p < 0.01) and α2 (p < 0.05) subunit of Na(+)/K(+)-ATPase, both PI3K subunits p85 (p < 0.01), p110 (p < 0.05), and association of IRS-1 with p85 (p < 0.05), while significantly decrease expression of AT1 (p < 0.05) and Rho A (p < 0.01) proteins. Our results suggest that estradiol in vivo in pathophysiological conditions, such as obesity accompanied with insulin resistance stimulates activity and expression of Na(+)/K(+)-ATPase by a mechanism that involves the participation of IRS-1/PI3K/Akt signaling. In addition, the decreasing level of AT1 and Rho A proteins estradiol probably attenuates the detrimental effect of obesity to decreased IRS-1/PI3K association and consequently reduce Na(+)/K(+)-ATPase activity/expression.
['Obradovic|Milan|M|', 'Zafirovic|Sonja|S|', 'Jovanovic|Aleksandra|A|', 'Milovanovic|Emina Sudar|ES|', 'Mousa|Shaker A|SA|', 'Labudovic-Borovic|Milica|M|', 'Isenovic|Esma R|ER|']
D000818:Animals D006332:Cardiomegaly D059305:Diet, High-Fat D004958:Estradiol D055504:Insulin Receptor Substrate Proteins D007333:Insulin Resistance D008297:Male D009206:Myocardium D009765:Obesity D019869:Phosphatidylinositol 3-Kinases D051057:Proto-Oncogene Proteins c-akt D051381:Rats D017208:Rats, Wistar D044140:Receptor, Angiotensin, Type 1 D015398:Signal Transduction D012964:Sodium D000254:Sodium-Potassium-Exchanging ATPase D054460:rho-Associated Kinases
High fat diet Estradiol Obesity Insulin resistance Sodium potassium adenosine-triphosphatase