替米沙坦对胰岛素抵抗大鼠心房肌L型钙通道α1C亚单位表达的影响

Effects of telmisartan on expressions of L-type calcium channel α1C subunit in the atrial myocardium in rats with insulin resistance

目的探讨胰岛素抵抗(IR)大鼠心房肌L型钙通道α1C亚单位(Cav1.2)的表达水平以及替米沙坦对其表达的影响。方法 32只IR OLETF大鼠随机分为2组,每组16只:IR模型组(M);IR+替米沙坦(5 mg·kg-1·d-1)组(T)。LETO大鼠16只为对照组(N)。20周后测定3组大鼠的血清胰岛素(FINS)、空腹血糖(FBG)、血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C),并计算胰岛素抵抗指数(HOMA-IR);用Western blot技术检测心房肌中Cav1.2的表达。结果与N组相比,M组FBG、TC、TG、LDL-C、FINS及HOMA-IR水平明显增高(P<0.05),而HDL-C水平明显降低(P<0.05),心房肌中Cav1.2表达水平明显降低(P<0.05);与M组相比,T组FBG、TC、TG、LDL-C、FINS及HOMA-IR水平明显降低(P<0.05),而HDL-C水平无明显变化(P=0.384),心房肌中Cav1.2表达水平明显升高(P<0.05)。结论 IR大鼠心房肌中Cav1.2表达降低;经替米沙坦干预后,IR大鼠心房肌中Cav1.2的表达水平回升。

ObjectiveTo determine the levels of expressions of L-type calcium channel α1C subunit（Cav1.2） in the atrial myocardium of rats with insulin resistance（IR）, and the effect of telmisartan on the Cav1.2 expression.MethodsThirty-two IR OLETF rats ware randomly divided into two groups of 16： IR model group （group M）; IR＋telmisartan （5 mg·kg-1·d-1） group （group T） for twenty weeks. Sixteen LETO rats were the normal control group （group N）. The plasma levels of fasting insulin（FINS）, fasting blood glucose（FBG）, serum total cholesterol （TC）, triglycerides （TG）, high-density lipoprotein cholesterol （HDL-C） and low-density lipoprotein cholesterol（LDL-C） were detected in three groups, and HOMA-IR was measured; the expression levels of Cav1.2 in atrium sinistrum tissue were measured by Western Blotting technique.Results Compared with group N, FBG, TC, TG, LDL-C, FINS and HOMA-IR were significantly increased （P〈0.05）, while the HDL-C level was significantly decreased （P〈0.05）, atrial muscle Cav1.2 expression levels were significantly lower in group M（P〈0.05）; compared with group M, FBG, TC, TG, LDL-C, FINS and HOMA-IR were obviously decreased （P〈0.05）, and the level of HDL-C had no significant changes （P=0.384）, atrial muscle Cav1.2 expression level increased in group T （P〈0.05）. ConclusionThese data indicate that the atrial myocardium Cav1.2 is down-regulated in IR rats; after telmisartan intervention, the expression level of atrial myocardium Cav1.2 increase in IR rats.