凝血酶对牛主动脉内皮细胞组织因子活性的影响及其与PKC传导途径的关系

The effect of thrombin on tissue factor activity in cultured bovine aortic endothelial cells and its correlation with PKC pathway

目的探讨凝血酶对内皮细胞组织因子（ＴＦ）活性的刺激作用及其与细胞内蛋白激酶Ｃ（ＰＫＣ）传导系统的关系。方法传代培养新生牛主动脉血管内皮细胞，取刺激或未受刺激的第４～８代细胞冻融液测定其ＴＦ活性。结果体外培养的血管内皮细胞在静息状态下ＴＦ活性极低（４．２０±１．１９）。与对照组相比，凝血酶的刺激使内皮细胞ＴＦ活性明显升高（ｎ＝８，Ｐ＜０．００１），且呈剂量依赖性关系（ｒ＝０．７８，Ｐ＜０．０５）和时间依赖性关系（ｒ＝０．８８，Ｐ＜０．０５）。ＰＫＣ抑制剂Ｈ７抑制凝血酶对内皮细胞ＴＦ活性的刺激作用（ｎ＝８，Ｐ＜０．０１），且抑制作用呈剂量依赖性。ＰＫＣ激动剂佛波酯也可刺激内皮细胞ＴＦ活性增高（３０．５９±３．７９，ｎ＝８，Ｐ＜０．００１），并可被Ｈ７阻断，ＰＭＡ对凝血酶的刺激作用没有显著影响。结论在凝血酶的刺激下，血管内皮细胞可产生较大量的ＴＦ；凝血酶对内皮细胞的这种刺激作用依赖于细胞内ＰＫＣ系统传导途径。

Objective To study the stimulating effect of thrombin on the expression of tissue factor(TF) activity in cultured bovine aortic endothelial cells (BAEC) and to elucidate if it is associated with the PKC system. Methods The BAECs were cultured after the Schwartz's method and one stage clotting time assay was used to measure TF activity in BAEC lysates. The TF activity was identified by EDGR Ⅶa and a monoclonal antibody against TF. Results Thrombin enhanced the expression of TF activity in cultured BAEC and the effect was dose (r=0.78,P<0.05,n=8) and time dependent (r=0.88,P<0.05,n=8). PMA, a PKC activator,also induced the expression of TF activity in BAEC. H 7, a protein kinase C inhibitor, inhibited the inductive effects of PMA and thrombin on TF in BAEC. Conclusion Thrombin can induce the expression of TF activity in cultured BAEC and the effect depends on PKC pathway.