Variation in yield and lethality of venoms from Iranian snakes.

The dangerous venomous terrestrial snakes of Iran belong to three groups: the Elapidae (cobras); the Viperinae (true vipers); the Crotalinae (pit vipers). Geographical distribution of each species was determined. Studies on the venoms extracted from the following Iranian snakes, Oxus cobra, Naja naja oxiana, Levantine viper (Afyi), Vipera lebetina, Carpet viper, Echis carinatus, Persian horned viper, Pseudocerastes persicus, Latifii viper, Vipera latifii, Mountain viper, Vipera xanthina and Caucasus pit viper (Agkistrodon halys), indicated that the yield of venom varies in each species. Venoms were compared for their lethality (i.v. LD50 in mice) and their rate of production. The antigenic components of the venoms were compared with their antisera by gel diffusion tests. To obtain the best results from antivenom treatment, the serum should be made against the venom of the local population of snakes or, at least, the commercial antivenom should be controlled for potency by testing with local reference venom.