胰岛素与硒对链脲佐菌素诱导的糖尿病大鼠心肌胰岛素信号转导的联合作用

Effect of combination of insulin and selenium on insulin signal transduction in cardiac muscle of STZ-induced diabetic rats

为阐明小剂量胰岛素(1u.kg-1)与硒(180μg.kg-1)对糖尿病大鼠糖脂代谢及其对心肌细胞胰岛素信号分子表达的联合作用,采用One TouchⅡ血糖仪和血糖试纸测定血糖水平;微柱法测定糖化血红蛋白浓度;酶学法测定甘油三酯(TG)和总胆固醇(TC)含量;免疫印迹和免疫组化法检测心肌细胞中PI3K和GLUT4表达的变化。结果表明,联合用药组血糖和血脂明显下降(P<0.01);同时联合用药明显增加糖尿病大鼠心肌细胞上PI3K和GLUT4的表达(P<0.01)。整体动物实验结果表明:胰岛素和硒联合应用在降低血糖和血脂方面发挥了协同作用;胰岛素与硒联合应用通过改善糖尿病大鼠心肌细胞胰岛素信号转导通路中PI3K的表达,从而改善了GLUT4的移位障碍,最终改善心肌的能量代谢。

This study is to investigate the effect of low doses of insulin（1 u·kg-1） and selenium（180 μg·kg-1） in combination on general physiological parameters and insulin signal molecules in cardiac muscle of STZ-induced diabetic rats.The levels of blood glucose were estimated using One Touch SureStep Blood Glucose meter.HbA1c levels were estimated using microcolumn assay.TG and TC were estimated using enzymatic assay.The levels of PI3K and GLUT4 in cardiac muscle were examined by immunoblotting and immunohistochemistry.The result showed that insulin in combination with selenium could significantly lower blood glucose and blood lipid levels and markedly restored the PI3K and GLUT4 levels in cardiac muscle.It could be concluded that there was cooperation between insulin and selenium,and that treatment of diabetic rats with combined doses of insulin and selenium increased cardiac glucose uptake by upregulating the level of PI3K-mediated GLUT4 in cardiac muscle,eventually ameliorating myocardial dysfunction.