cAMP依赖性蛋白激酶在血管平滑肌细胞增殖周期中的变化

VARIATION OF cAMP-DEPENDENT PROTEIN KINASE IN PROLIFERATION OF VASCULAR SMOOTH MUSCLE CELLS

以培养的兔胸主动脉平滑肌(ASMC)为材料,研究了cAMP依赖性蛋白激酶(PK—A)在细胞增殖周期中的变化规律。胞浆PK—A在ASMC增殖周期中的变化规律为:从G_0期进入G_1期,酶活性逐渐下降,至G_1中期(6h)降至最低(2％)。随后开始升高,G_1晚期(9h)有一短暂高峰(52％);DNA合成之前又(12h)降至3％(以G_0期酶活性为100％)。核内PK—A在ASMC增殖周期中的变化规律:从G_0期进入G_1期酶活性急剧下降,G_1早期(3h)酶活性为27％,,随后逐渐升高,G_1晚期酶活性达285％,DNA合成之前降至130％(以G_0期酶活性为100％)。结果提示PK—A对ASMC有促进增殖作用。

Variation of cAMP-dependent protein kinase (PK-A) activities in cell cycle of cultured rabbit aortic smooth muscle cells (ASMC) was studied. In cell cytosol, with the entry of Go cells into cell cycle, there was a decrease in PK-A activity with a trough at 6hr and an increase in late G1 with a peak at 9hr. In nuclear, with the entry of Go cells into cell cycle, also there was a decrease in PK-A activity as in cytosol with the lowest point at 3hr. and an increase in late G1 with a peak at 9hr. These results suggest that PK-A may play a positive effect on the proliferation of ASMC.