胰岛素对NIH3T3细胞生长和Ras-MAPK信号途径的影响

目的 探讨胰岛素激活的Ras-MAPK信号途径对鼠成纤维细胞（NIH3T3细胞）生长的影响。方法 藉四唑蓝比色法（MTT法）和蛋白免疫印迹试验分别观察胰岛素对NIH3T3细胞生长和胞内丝裂原激活蛋白激酶（MAPK）活性的影响。结果 胰岛素对NIH3T3细胞的促增殖作用呈时间和浓度依赖性，10mU/ml胰岛素对NIH3T3细胞的促增殖作用效果最佳，对NIH3T3细胞作用的EC50是0.2mU/ml(48h);0.14mU/ml(72h)。MAPK在10mU/ml胰岛素刺激1min后即出现酪氨酸磷酸化，10min达到高峰。胰岛素作用10min，MAPK酪氨酸磷酸化程度随浓度增高（0.1,1.0,10mU/ml)而递增。结论 胰岛素对NIH3T3细胞促增殖作用与激活Ras-MAPK信号途径相关。

Effects of Insulin on Proliferation of NIH3T3 Cells and Ras-MAPK Signal Transduction Pathway

Objective\ To study the effect of Ras\|MAPK signal transduction pathway activated by insulin on proliferation of mouse fibroblasts(NIH3T3 cells).\ Methods\ The growth and activation of mitogen\|activated protein kinase(MAPK) of NIH3T3 cells treated with insulin were investigated with MTT cell count method and western\|blotting methods respectively.\ Results\ Insulin enhanced the proliferation of NIH3T3 cells, depending on its dose and time used.\ 10 mU/ml insulin was the best dose.\ The EC\-\{50\} of insulin on NIH3T3 cells was 0 2 mU/ml and 0 14 mU/ml at 48 hours and 72 hours respectively.\ \{Insulin\} induced the activity of tyrosine phosphorylation of MAPK rapidly, and was detectable at 1 min, reached maximum at 10 min, and the degree of tyrosine phosphorylation of MAPK was higher at 10 min when the dose of insulin increased from 0 1 to 10 mU/ml.\ Conclusion\ The effect of insulin on proliferation of NIH3T3 cells relates to Ras\|MAPK signal transduction pathway.