蝮蛇毒蛋白C激活物对凝血系统的影响

目的研究蝮蛇毒纯化蛋白C激活物(PCA)的抗凝机制。方法测定PCA对正常人混浆KPTT、PT、TT的影响,对血液凝血活酶生成试验(BTGT)及PA二期法的影响以及对白兔的KPTT和Fgn的影响。结果PCA在最终浓度为0.025mg/L时对正常人混浆KPTT可明显延长,但PT和TT不受影响;当它的浓度增加到50mg/L,PT也可延长,但TT依然无明显变化;最终浓度为0.0125mg/L时,血液凝血活酶生成明显受抑制;当它的浓度增加到2.5mg/L,凝血酶生成显著减少,但抗凝血酶时间始终无明显变化;PCA可明显延长白兔的KPTT。结论PCA在低浓度时首先抑制凝血系统第一阶段内凝途径,在高浓度时也妨碍外凝途径或共同途径,BTGT和PA二期法比KPTT和PT敏感;PCA具有体内抗凝作用。

The action of protein C activator from venom of Agkistrodon halys Pallas on blood coagulant system

Objective To study anticoagulant mechanism of protein C activator(PCA)purified from venom of Agkistrodon halys Pallas.Methods To measure KPTT,PT,TT of pooled human plasma;blood thromboplastin generation test(BTGT) and prothrombin assay(PA) two-stage method;KPTT and Fgn in rabbit in the presence of PCA. Results The PCA of 0.025mg/L at final concentration was showed to prolong KPTT of pooled human plasma but not PT and TT,while the dosage of the PCA was increased to 50mg/L,PT might also be prolonged,but TT remained unaffected;The PCA of 0.0125mg/L at final concentration can remarkable inhibit blood Thromboplastin generation,but antithrombin time not remained unaffected;The PCA obviously prolong KPTT in rabbit. Conclusion The PCA may preferentially inhibit blood coagulation in intrinsic clotting pathway of the first stage of coagulation system at low concentration;however,it may also intefere with blood coagulaion in extrinsic clotting pathway or commom pathway at high concentration;BTGT and PA two-stage method are sensitive than KPTT and PT;The PCA has anticoagulant effect in vivo.