The red wine polyphenol resveratrol induced relaxation of the isolated renal artery of diabetic rats: The role of potassium channels

The effect of resveratrol on vasculature of diabetic animal is not defined. This study was aimed at evaluating how alloxan-induced diabetes alters the relaxation of the isolated rat renal artery (RA) to resveratrol and determining whether prolong hyperglycemia modifies the expression of potassium (K) channels in the wall of RA. Diabetes reduced the sensitivity to resveratrol in RA. According to K channel blocker affinity, it seems that different sub-type of K channels were involved in the resveratrol-induced relaxation of RA of normal rats and only voltage-sensitive Kvl channels took part in the resveratrol effect on the RA of diabetic rats. Endothelial dysfunction developed during diabetes led to down-regulation of the expression of almost all tested K channels, while up-regulation of Kv1.3 channel expression was only noticeable. Having in mind that Kv1.3 channels have a prominent role in insulin signalling, these results suggest renovascular protective effect of resveratrol in diabetes.