血管紧张素Ⅱ对心肌细胞c-myc蛋白表达的作用

目的 探讨钙内流及钙释放对心肌细胞c-myc蛋白定位及半定量表达有何影响。方法 应用血管紧张素Ⅱ（Ang Ⅱ，10^7mol/L)刺激原代培养的大鼠心肌细胞钙内流、雷尼丁（RY，10^7mol/L)刺激胞内钙释放；免疫组织化学方法检测心肌细胞。myc蛋白定位表达，免疫印迹（Western blot)检测心肌细胞c-myc蛋白半定量表达。结果 免疫组织化学方法显示，RY诱导的心肌细胞c-myc蛋白表达及核转位表达早于Ang Ⅱ。Western bolt显示，Ang Ⅱ及RY刺激2h时，c-myc蛋白明显表达，24h下降，2、3、5d呈逐渐增加趋势，各时相点与24h比较差异显著（P＜0．05或0．01）。结论 c-myc蛋白表达与细胞内钙浓度变化有关，与钙的来源无关。

The effect of calcium activator on the expression of c-myc protein

Objective To investigate the effect of extracellular influx and intracellular release of calcium from stores on expression and disribution of c-myc protein. Methods Calcium influx and releasing of cultured neonatal rat cardiomyocytes were stimulated by Angiotensin II ( Ang Ⅱ , 10-7 M and Ryanodine (RY, 107 M ) respectively, the expression of c-myc protein of cardiomycytes were localized by immunohistochemistry and analyzed by western blot semi-quantitatively. Results Immunohistochemistry revealed that the expression of c-myc protein and translocation expression after stimulated by RY was earlier than that of stimulated by RY. Western Blot showed that c-myc protein of cardiomycytes expressed apparently at 2h, decline at 24h, with a significant increment at 2, 3, 5day later, by stimulations of AngⅡ and RY. C-myc protein expressed at 24h is significantly different from those expressed at other time(P＜0.05 or 0.01 ). Conclusion The expression of cmyc protein is correlated with intracellular calcium change, but not to its resources.