Effects of Endothelin-A Receptor Antagonist BQ-123 on Plasma Leptin Levels Streptozotocin Induced Diabetic Rats

Abstract

Objectives: Leptin and Endothelin (ET) as important endogenous factors interact with each other which may contribute to a better understanding their role in diabetic pathogenesis. We aimed to evaluate the relationship between Leptin and ET by investigating the influence of BQ-123, an ET-A receptor (ET A R) antagonist, on Leptin levels in rats with diabetes induced by Streptozotocin (STZ). Methods: In this study, 24 male Wistar-albino rats were divided into three groups; Control, STZ, STZ+BQ-123 groups. Experimental diabetes was induced by delivering a single dose of 60 mg/kg intravenous STZ. The rats in the STZ+BQ-123 group received 4 mg/kg i.v.in total BQ-123 (2 mg/kg +2 mg/kg on the 39th and 40th days). The plasma specimens collected 6 hours after the last BQ-123 delivery were studied for biochemical parameters. Results: At the end of the experiment, the weights of rats in the STZ and STZ+BQ-123 groups were significantly lower compared with the values in the Control group. The levels of blood glucose were significantly higher in the STZ and STZ+BQ-123 groups than in the Control group. While rats with STZinduced diabetes demonstrated no changes in Leptin, PC and K + levels, they exhibited reduced NO, Na + and Clconcentrations. The levels of plasma TBARS was significantly higher in the STZ group than in the Control and STZ+BQ-123 groups. Conclusion: Although the levels of plasma Leptin was no statistically significant difference between the groups, BQ-123 groups lead to further decrease in reduced levels of Leptin than only diabetic group. Our findings have been considered that ET A R antagonists have positive impacts depending on the dosage in the diabetic rats.