Contribution of ATP-Sensitive K^+ Channels to Contraction of Rat Tail Artery is Significantly Reduced in Males but Not Females Rats in Streptozotocin-Induced Diabetes: Pharmacological Analysis

The aim of this article is to find out possible gender differences of participation of ATP-sensitive potassium channels in regulation of contractility in vascular smooth muscles of rats with diabetes. We used isolated tail artery of both genders rats with streptazotocin-induced diabetes (SID). After 3 weeks, we compared concentration-effects curves obtained with phenylephrine (0.1 to 300 μM) in the presence of 100 μM of diazoxid in control and SID rats of both genders. Diazoxide at 100 μM concentration significantly antagonizes concentration-dependent contraction of tail artery induced by phenylephrine in both male and female control rats. However, this antagonism disappeared in male but not female rats treated by streptozotocin. Our results indicate that SID leads to downregulation or functional malformation (lack of reaction to the opener) of ATP-sensitive potassium channels in males, but not in females rats. This observation has to be confirmed by immunochemistry analysis and taking into account in humans.