多巴胺D1类受体对胰岛素受体介导的血管平滑肌细胞增殖的影响

目的 观察多巴胺D1类受体对胰岛素受体介导的血管平滑肌细胞增殖的影响.方法 本研究以A10细胞为研究对象,观察刺激D1类受体对胰岛素促增殖作用的影响,并用免疫印迹研究D1类受体影响胰岛素作用的机制.细胞增殖作用采用3H]胸腺嘧啶核苷(3H-TdR)掺入量表示.结果 胰岛素可促进A10细胞的增殖,该作用呈现浓度依赖性的.D1类受体激动剂Fenoldopam本身对A10细胞无增殖影响,但Fenoldopam通过D1类受体可完全阻断胰岛素介导的血管平滑肌细胞增殖作用.免疫印迹显示刺激D1类受体可降低胰岛素受体的蛋白表达,提示该机制可能参与了D1类受体对胰岛素受体作用的过程.结论 D1类受体对胰岛素受体介导的血管平滑肌细胞增殖具有抑制作用,该作用可能在高血压的发生发展中发挥一定作用.

Effects of D1-like Dopamine Receptor on Insulin Receptor-mediated Proliferation of Vascular Smooth Muscle Cells

Objective To investigate the role of Dl-like dopamine receptor on insulin receptor-mediated proliferation of vascular smooth muscle cells. Methods A10 cells were used in this study and the mechanisms of Dl- like receptor on insulin receptor was determined by immunoblotting. The proliferation of VSMC cells was deter- mined by -3H]-TdR incorporation. Results Insulin increased proliferation of A10 cells in a concentration-de- pendent manner. Dl-like receptor, by itself, had no effect on cell proliferation, but blocked the insulin-mediated proliferation of A10 cells. Immunoblotting results showed that activation of Dl-like receptor by fenoldopam inhibited the insulin receptor expression, which might take part in the inhibitory effect of D1-like receptor on insulin receptor-mediated cell proliferation. Conclusion Activation of D1-like receptor inhibits insulin receptor-mediated proliferation of vascular smooth muscle cells, which might be involved into the pathogenesis of essential hypertension.