The toxicity and immunological properties of some sea-snake venoms with particular reference to that of Enhydrina schistosa

Abstract

Toxicity tests were made on a number of snake venoms but special attention has been paid to Enhydrina schistosa venom. The toxic fraction of E. schistosa venom is rapidly destroyed by heat and readily passes through a cellophane dialysis sac. The LD50 dose for a variety of laboratory mammals and one species of fish is 40 to 120 μg./kg. For the frog it is 20 μg./kg. Electrophoretic analysis at pH 6.8 showed that the toxic fraction of the venom was more electropositive than the other components. Various methods of producing an antivenom were attempted. Using Freund's incomplete adjuvant, an antiserum was prepared of which 1.0 ml. was required to neutralize 100 mouse LD50 of venom, using an in vitro testing method. Immunoelectrophoretic analysis suggested that the toxic fraction of the venom is less antigenic than the other protein components. By in vitro testing, E. schistosa antivenom afforded significant cross protection against Hydrophis cyanocinctus and Hydrophis spiralis venoms. Antivenoms to krait, cobra and a polyvalent antivenom to Indian cobra, krait, Echis and Russell's viper afforded negligible neutralization of E. schistosa venom.