3种钙激动剂促培养的大鼠血管平滑肌细胞增殖

目的：探讨不同来源的细胞内钙离子（Ca²⁺]i）对血管平滑肌细胞（vascular smooth muscle cells, VSMCs）丝裂素活化蛋白激酶（MAPK）介导的增殖反应的作用。方法：以培养的大鼠VSMCs为靶细胞，用血管紧张素II（Ang Ⅱ）剌激VSMCs跨膜Ca²⁺内流、三磷酸肌醇（IP₃）和雷尼丁（RY）剌激胞内Ca²⁺释放，γ-³² P]-ATP掺入法和免疫印迹（Western blot）测MAPK活性及蛋白含量，氚-亮氨酸（³H]-Leu）、氚-胸腺嘧啶（³H]-TdR）掺入量作为VSMCs增殖的指标。结果：Ang Ⅱ、IP₃和RY均能显著增加VSMCs的Ca²⁺]i浓度、MAPK活性及蛋白含量，并提高³H]-Leu、³H]-TdR掺入量，与对照组VSMCs相比差异显著（P<0.01）。结论：钙激动剂诱导的MAPK活性及含量的增加参与了VSMCs的增殖，VSMCs的肥大增殖与Ca²⁺]i浓度增加有关，而与Ca²⁺]i的来源无关。

Effects of three kinds of calcium activator on the proliferation

AIM: To investigate the effects of intracellular free calcium (Ca²⁺]i) from different resources on the proliferation mediated by mitogen activated protein kinase (MAPK) in vascular smooth muscle cells (VSMCs). METHODS: Cultured VSMCs were used in all experiments. Calcium influx was stimulated by angiotension Ⅱ(Ang Ⅱ). The release of intracellular calcium stores was induced by inositol trisphosphate (IP₃) and ryanodine (RY). MAPK activity was measured by γ-³²P]-ATP incorporation MAPK protein expression by western blot, VSMCs proliferation by ³H]-Leucine (³H]-Leu) and ³H]-Thymidine (³H]-TdR) incorporation. RESULTS: Compared to the control VSMCs, Ang Ⅱ, IP₃ and RY significantly increased Ca²⁺]i concentration activity of MAPK and its protein content in VSMCs. The promotion of ³H]-Leu and ³H]-TdR incorporation in VSMCs was also observed (P<0.01). CONCLUSION: The study indicated that calcium activator-induced increase in the activity and protein content of MAPK was involved in the proliferation of VSMCs, which was closely related to the Ca²⁺]i concentration but independent to its origin.