[Modification of the toxicity of Bothrops atrox poison by interventions in the coagulation and kallikrein system of prey].

LD50-determinations with venom mixtures from different age groups of Bothrops atrox were carried out on differently pretreated mice. No differences were seen in the LD50 when comparing untreated mice with mice previously defibrinogenated with batroxobin. Inhibition of the coagulation-, kallikrein-kinin- and fibrinolytic system by pretreatment with batroxobin and aprotinin led to a significantly decreased toxicity of the venom mixtures of all age groups. The age-related difference in toxicity had practically disappeared. Furthermore, the number of mice of the latter group dying within one hour after the venom injection was strongly reduced as compared to untreated and only batroxobin-treated animals. Tests performed on rats showed that the rapidly occurring lethality following the venom injection as a consequence of circulatory disturbances (strong fall of arterial blood pressure, bradycardia, dyspnea), may be prevented almost completely by preincubation of the venom with aprotinin.