替米沙坦对2型糖尿病大鼠心肌脂联素受体2葡萄糖转运蛋白4表达的影响

目的探讨替米沙坦对2型糖尿病大鼠心肌组织脂联素受体2(AdipoR2)及葡萄糖转运蛋白4(GluT4)表达的影响。方法30只雄性Wistar大鼠,随机分为3组:健康对照组(A组),糖尿病组(B组)和糖尿病替米沙坦治疗组(C组),每组各10只。采用高糖高脂饮食加小剂量链脲佐菌素(STZ)的方法诱导糖尿病模型。用逆转录-聚合酶链反应(RT—PCR)的方法测定大鼠心肌AdipoR2mRNA、GluT4mRNA的表达,用免疫组织化学法检测AdipoR2蛋白在心肌组织中的表达,用放射免疫法检测血浆脂联素水平。结果与A组比较,B组糖尿病大鼠心质量/体质量增加,血浆脂联素水平、心肌AdipoR2mRNA和蛋白表达以及GluT4mRNA表达均显著降低。替米沙坦治疗后,C组糖尿病大鼠心质量/体质量降低,血浆脂联素水平、心肌AdipoR2mRNA和蛋白表达以及GluT4mRNA表达均显著升高。结论2型糖尿病大鼠心肌AdipoR2及GluT4表达水平降低。替米沙坦上调2型糖尿病大鼠心肌AdipoR2及GluT4表达,促进心肌葡萄糖氧化,减轻心脏肥大,产生心脏保护作用。

Effects of telmisartan on the expression of AdipoR2 and GluT4 in the heart of type 2 diabetic rats

Objective To investigate the effects of Telmisartan on the expression of AdipoR2 and GluT4 in the hrart of type 2 diabetic rats. Methods Thirty male Wister rats were randomly divided into three groups： normal control group （group A）, diabetic group （group B）, and Telmsisartan-treated diabetic group （group C）. Type 2 diabetes in rats was induced by high-fat and high-sugar diet plus a low-dose injection of streptozotocin （STZ） by abdominal cavity. The mRNA expressions of myocardial AdipoR2 and GluT4 were measured by RT-PCR and the protein expression of myocardial AdipoR2 by immunohistochemieal staining. Plasma adiponeetin levels were measured by radioimmunoassay. Results Compared with group A, untreated diabetic rats （group B） showed higher ratio of heart to body weight, significantly reduced plasma adiponectin, protein and mRNA expressions of myocardial AdipoR2 and mRNA expression of myocardial GluT4. With Telmisartan treatment, group C showed lowered ratio of heart to body weight, significantly increased plasma adiponectin, protein and mRNA expressions of myocardial AdipoR2, and mRNA expression of myocardial GluT4. Conclusion Reduced expressions of myocardial AdipoR2 and GluT4 were identified in type 2 diabetic rats. Telmisartan was shown to have a cardioprotective effect in diabetic rats through up-regulation of Adi- poR2 and GluT4 expressions and promotion of glucose oxidation in myocardium and reduction of cardiac hypertrophy.