The Role of pp60 c-src in Thrombin-induced VSMCs Proliferation

Objective To investigate the effect of thrombin on Vascular Smooth Muscle Cells (VSMCs) proliferation and the role of pp60 c-src activity on thrombin-induced VSMCs proliferation.Methods Growth-arrested VSMCs (3-10 generation ) were used in the experiment. The activity of pp60 c-src in cells was assayed by immunoprecipitation. Cell proliferation was quantified by MTS method.Results ①Either thrombin group (0.5 or 1.0 umol /ml) presents similar cell proliferation curves with two peaks occurring at 1 h(P(0.05)) and at 24 h(P0.05). ②Compared with 0h, the activity of pp60c-src in thrombin group increased significantly at 1 h(P(0.05))and at 12 h(P0.05).Compared with thrombin group, PP1 decreased the thrombin-induced cells proliferations at 1 h(P0.05) and at 24 h(P0.05).Conclusion ①Cell proliferation induced by thrombin had two peaks at 1 hr and 24 hr. This indicated that induction of thrombin may not be only quickly and transient but also torpid and late. ②The increase of pp60c-src activity occurs before cell proliferation, which suggests that pp60c-src is involved in signal transmission pathway of thrombin-induced cell proliferation.