Cross-neutralization on the histamine-releasing activity of snake venoms.

This paper investigates the neutralizing effect of crotalic and bothropic antivenoms on the histamine-releasing activity of three different Brazilian snake venoms (Crotalus durissus terrificus, Bothrops jararacussu and Bothrops alternatus). This relative histamine-releasing activity was determined on peritoneal mixed cells of rats. C. d. terrificus venom was the most efficient histamine-releasing agent (ED50 = 1.25 micrograms/ml) followed by B. jararacussu (ED50 = 1.97 ug/ml) and B. alternatus (ED50 = 15.1 ug/ml) venoms. The histamine-releasing effects eventually produced by antivenom sera (antivenoms) were avoided by the use of small volumes of each one (10-20 ul). Both the monovalent crotalic and the polyvalent bothropic antivenoms were able to neutralize the histamine-releasing activity of the three venoms without specificity. This cross-reaction suggests that the main histamine-releasing factor (s) present in these venoms has similar antigenic constitution.