Effect of rosiglitazone on blood pressure in rats with diabetes mellitus accompanying hypertension and its mechanism

Objective To study the effect of rosiglitazone on blood pressure in rats with diabetes mellitus(DM) accompanying hypertension.Methods Twenty-four rats with spontaneous hypertension were included in this study.A rat DM accompanying hypertension model was established by intraperitoneal injection of streptozotocin.The rats were divided into control group(n=12) and rosiglitazone treatment group(n=12).Four weeks after streptozotocin treatment,the serum nitric oxide(NO) and nitric oxide synthase(NOS) levels were measured.The animals were then sacrificed and their interventricular septum was removed.Expressions of vascular endothelial receptor A(ETRA) and vascular endothelial receptor B(ETRB) in interventricular septum tissue were detected with immunohistochemical staining.Results The blood pressure was significantly lower in rosiglitazone treatment group than in control group(P0.05).The serum NO and NOS levels were significantly higher in rosiglitazone treatment group than in control group(P0.01).No significant difference was found in ETRA expression of rosiglitazone treatment group(P0.05).However,the ETRB expression level was significantly higher in rosiglitazone treatment group than in control group(P0.05).Conclusion Rosiglitazone can significantly reduce the blood pressure in rats with DM accompanying hypertension by selectively up-regulating the ETRB expression and increasing the activity of NOS and the synthesis of NO,thus promoting vasodilation.