Capacity of Thai green pit viper antivenom to neutralize the venoms of Thai Trimeresurus snakes and comparison of biological activities of these venoms.

The capacity of Thai green pit viper antivenom raised to Trimeresurus albolabris to neutralize the venoms from six species of Trimeresurus sp. in Thailand has been examined. They were Trimeresurus albolabris, T. macrops, T. popeiorum, T. hageni, T. purpureomaculatus, and T. kanburiensis. The antivenom neutralized lethal and hemorrhagic activities of all these venoms. The capacity of antivenom to neutralize lethal toxicity of the venom was expressed as the amounts (mg) of snake venom neutralized by 1 ml of the antivenom. The largest capacity was found with the homologous venom. Results of immunodiffusion, immunoblotting, and antigen-antibody complex formation experiments supported the results of neutralization experiments. Several biological activities of the Trimeresurus venoms were also examined and compared. They were lethal, hemorrhagic, proteolytic, phospholipase A, arginine ester hydrolyse, and thrombin activities. There was no correlation between the ratios of lethal toxicity and hemorrhagic activity, lethal toxicity and phospholipase A activity, as well as hemorrhagic activity and proteolytic activity.