NIDDM大鼠骨骼肌组织GLUT4 mRNA表达及其与胰岛素分泌关系的实验研究

Experiment study of the GLUT4 mRNA expression in the skeletal muscle and the relationship between GLUT4 mRNA expression and insulin secretion in NIDDM rats

目的观察非胰岛素依赖型糖尿病(NIDDM)大鼠骨骼肌葡萄糖转运体4(glucosetransporter4,GLUT4)mRNA表达及其与胰岛素分泌的关系。方法制备NIDDM大鼠模型 ,用Northernblot方法测定骨骼肌组织中GLUT4mRNA表达量 ;放射免疫法测定血清胰岛素含量 ;免疫组化法观察胰岛胰岛素阳性 β细胞。结果NIDDM大鼠骨骼肌GLUT4mRNA表达显著低下 ,仅为对照组的45 %(P<0.01) ;其空腹基础胰岛素水平正常,但葡萄糖耐量试验胰岛素水平较对照组明显降低,2h胰岛素分泌有延迟现象 ;免疫组化实验NIDDM大鼠胰岛体积减少一半以上 ,胰岛素阳性 β细胞数量明显减少。结论NIDDM大鼠骨骼肌GLUT4mRNA表达量低下 。

Aim To observe the glucose transporter 4 (GLUT4) mRNA expression in the skeletal muscle and the relationship between GLUT4 mRNA expression and insulin secretion in non-insulin-dependent diabetes mellitus (NIDDM) rats.Methods The rat models of NIDDM were made. The GLUT4 mRNA expression in skeletal muscle was observed with Northern blot method. The serum insulin was determined by radioimmunoassay. The change of insulin positive β cell in islet was observed by immunohistochemistry.Results The GLUT4 mRNA expression in skeletal muscle in NIDDM rats was decreased to 45% of that in normal rats (P<0.01).The fast serum insulin level was normal, but in oral glucose test, the secretion of insulin was reduced markedly and a phenomenon of delayed secretion was observed. Immunohistochemistry experiment displayed that the volume of islet in NIDDM rats was smaller than half of that in normal rats and the number of insulin positive β cells reduced markedly.Conclusion The present study showes that in NIDDM rats the GLUT4 mRNA expression in skeletal muscle is lower and this response is considered to have some positive correlation with insulin secretion.