Effects of convulxin, a toxin from rattlesnake venom, on platelets and leukocytes of anesthetized rabbits

Abstract Convulxin is a high molecular weight toxin isolated from rattlesnake ( Crotalus durissus terrificus, Crotalus durissus collilineatus, Crotalus durissus cascavella ) venom. When administered i.v. it reduces the number of circulating platelets and leukocytes of anesthetized rabbits in a dose dependent manner. Small doses induce reversible platelet aggregation, and larger doses cause lysis. The doses of convulxin that cause platelet lysis also evoke cardiovascular and respiratory disturbances in anesthetized animals. These effects were also observed when platelets which were preincubated with convulxin in vitro were administered to animals which had received antivenom serum. This indicates that convulxin may act by releasing substances contained in the platelets.