丝裂素活化蛋白激酶参与钙激动剂介导的心肌肥大

Mitogen activated protein kinase in calcium activator mediated cardiomyocyte hypertrophy

目的 :探讨不同来源的细胞内钙 ([Ca2 +] i)对心肌细胞丝裂素活化蛋白激酶 (MAPK)介导的心肌细胞肥大反应的作用。方法 :以培养的大鼠心肌细胞为模型 ,用血管紧张素 (Ang )刺激心肌细胞外 Ca2 +跨膜内流、三磷酸肌醇 (IP3 )刺激胞内 Ca2 +释放 ,γ-3 2 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(3 H-L eu)、氚 -胸腺嘧啶 (3 H-Td R)掺入量作为心肌细胞肥大的指标。结果 :Ang ,IP3 刺激 15 min均能显著增加心肌细胞 MAPK活性及蛋白含量 ,并提高 3 H-L eu,3 H-Td R掺入量 ,与对照组心肌细胞相比差异显著 (P<0 .0 1)。结论 :钙激动剂诱导的 MAPK活性及含量的增加参与了心肌细胞肥大 ,心肌细胞的肥大与 [Ca2 +] i

AIM:To investigate the effect of intracellular free calcium ([Ca 2+ ] i) from different sources on the hypertrophy of cardiomyocytes mediated by mitogen activated protein kinase (MAPK). METHDOS:Calcium influx was stimulated with angiotension Ⅱ(AngⅡ),calcium was released with inositol (1,4,5) trisphosphate (IP 3) in cultured rat cardiomyocytes, MAPK activity and MAPK protein expression were measured by γ 32 P ATP incorporation and by western blot respectively;cardiomyocytes hypertrophy was marked by 3H Leucine( 3H Leu) and 3H Thymidine( 3H TdR) incorporations. RESULTS:AngⅡ and IP 3 could increase MAPK activity and MAPK protein content,and promote 3H Leu and 3H TdR incorporations in cardiomyocytes,which were significantly different from those of the controlled cardiomyocytes( P <0.01). CONCLUSION:cardiomyocyte proliferation closely related with the [Ca 2+ ] i concentration.