| Type2diabetes and hypertension are core risk factors of clinical cardiovascularevents, and both of them express familial aggregation of incidence. Studies have shownthat incidence of the patients with hypertension accompanied by diabetes is much higherthan the normal population, causing cardiovascular complications more severe. And theincidence of stroke and myocardial infarction of hypertension-diabetic patients is4-8times higher than normal population. So, the treatment of hypertension accompanied bydiabetes is of great clinical significance.As an insulin sensitizer, rosiglitazone is the main representative of thethiazolidinediones (TZDs), and it is widely used among type2diabetes patients exceptthose accompanied by class III and IV heart failure patients according to the New YorkHeart Association (NYHA). The function of it include: anti-lipolytic, protecting thefunction of β-cell function, increasing muscle glucose uptake and reducing hepatic glucoseproduction, stably controlling the blood glucose level. More importantly, it can avoid lowblood glucose and weight gain caused by the traditional treatment. A growing number ofstudies have shown that apart from the improvement in insulin resistance and glucolipidmETRAbolism, rosiglitazone also can improve endothelium-dependent vasodilation andreduce the blood pressure of hypertensive patients with type2diabetes. The clinicaltrial-PROactive studies further indicate that pioglitazone can reduce the occurrence of all-cause death, nonfatal myocardial infarction, and stroke among high-risk cardiovascularpatients with diabetes. However, the mechanisms underlying their depressurization andvascular effects are remain unclear.AimsTo investigate the effects of rosiglitazone on the blood pressure of hypertensive-diabeticrats and the underlying mechanisms.MethodsIn our study, hypertensive-diabetic rat model was induced by streptozotocin (STZ) fromspontaneously hypertensive rat(SHR). And then the rats were treated with rosiglitazone inthe following4weeks. After the termination of the treatment, the blood pressure wasmeasured to indicate the potential influence of rosiglitazone on it. Meanwhile, the septummyocardial tissues were prepared for immumohistochemical staining and RT-PCR toreveal the expression of type A and B endothelin receptors, we also detected the levels ofnitric oxide (NO) and nitric oxide synthase (NOS) in the serumResultsFollowing the4weeks rosiglitazone treatment, the blood pressure was markedlyreduced in rosiglitazone-treated rats, with significant differences compared with controlgroup（P<0.05）. In addition, for rosiglitazone-treated rats, endothelin Areceptor level wasof no significant changes（P<0.05）, while ETRB level and ETRB mRNAexpression wassignificantly increased（P<0.05）. In addition, comparing to the control group, both NOand NOS were significantly increased in rosiglitazone-treated rats (P<0.01).ConclusionsRosiglitazone is a effective therapy for high blood pressure which was accompanied bydiabetes, and such therapy effect is correlated with the selective upregulation of endothelinB receptor, enhancement of NOS activity and promotion of vasodilator NO synthesisfollowing the rosiglitazone treatment. |
