Rosiglitazone Amends Myocardial Microvascular Endothelial Function in Diabetic Rats

Objective To investigate the effect of rosiglitazone treatment on cardiac microvascular endothelial cell function in diabetes mellitus rats.Methods Type 2 diabetic rats were induced by an intraperitoneal injection of low doses of streptozotocin combined with high fat diet,and were randomized to rosiglitazone treatment(4mg/kg/d) or vehicle treatment for 16 weeks.Plasma soluble endothelial protein C receptor(sEPCR),soluble thrombomodulin(sTM),von Willebrand factor(vWF),and nitric oxide(NO) were determined.The NO concentration and all isoforms of nitric oxide synthase(NOS) activity of cardiac tissue homogenate and expression of endothelial nitric oxide synthase(eNOS) were detected by spectrophotometer and immunohistochemistry,respectively.Results The levels of sEPCR,sTM,and vWF and the level of plasma glucose were significantly lower in diabetic rats treated with rosiglitazone compared with untreated group but higher than non-diabetic control.Compared with untreated group,the NO concentration and constitutive NOS(cNOS) activity and the expression of eNOS in myocardium in diabetic rats treated with rosiglitazone were significantly increased,but the inducible NOS(iNOS) activity in diabetic rats treated with rosiglitazone was significantly reduced.Conclusion Rosiglitazone significantly reduces blood glucose and amends cardiac capillary endothelial function in type 2 diabetic rats.It is suggested that rosiglitazone administration may attenuate the development of cardiac microvascular disease in diabetes.