The Activation of Platelet Induced by the Venom of Trimeresurus Mucrosquamatus (From Hunan Province)

Trimeresurus Mucrosquamatus venom (TMV) induced the concentration-dependent aggregation of platelets of different species.The threshold concentrations of TMV inducing the platelet aggregation of human,rabbit,dog and Guinea pig were 2.0,12.5,2.0 and 0.6 μg/Ml respectively.EDTA interfered with the platelet aggregation by TMV,but heparin did not prevent the action of TMV.The platelet aggregation induced by TMV was accompanied by the release of serotonin (5-HT) from the challenged platelets.The concentration of TMV which induced the maxium release of 5-HT (72%) from rabbit platelets was 100 μg/Ml.The TMV also induced the formation of Thromboxane A2 (TXA2) of platelets.The inhibition of cyclo-oxygenase with apirin,which reduced and abolished the formation of TXA2,but did not suppress platelt aggregation induced by TMV.Thus,thromboxane-independent mechanisms should account for platelet activation with TMV.Our preliminary results shown that TMV is a good tool for studying the activation of platelets.