CHARACTERIZATION OF THE BIOLOGICAL-ACTIVI TIES OF THE YELLOW AND WHITE VENOMS FROM CROTALUS-DURISSUS-RURUIMA COMPARED WITH VENOM FROM CROTALUS-DURISSUS-TERRIFIOUS - NEUTRALIZATION OF CROTALUS-DURISSUS-RURUIMA VENOMS BY ANTIVENOMS

The biological activities of 'yellow' and 'white' venom of a rattlesna ke Crotalus durissus ruruima Hoge, 1965, found in the savanna-like veg etation (cerrado) of northern Brazil (Roraima) and Venezuela have been studied, and compared to the reference Crotalus durissus terrificus v enom. The lethal activity of venoms depended on the inoculation route. The most toxic venom was the white one. The venoms of C. d. terrificu s and the yellow of C. d. ruruima had similar lethalities. The yellow venom of C. d. ruruima showed a caseinolytic activity three times high er than that obtained with either the venom of C. d. terrificus or the white one of the C. d. ruruima. Hemorrhagic and necrotic activities w ere found only in the yellow venom. White and yellow venoms from C. d. ruruima showed a similar action on fibrinogen; this thrombin-like act ion was greater with C. d. terrificus venom. On histopathological sect ions local and pulmonary hemorrhage was found only with the yellow ven om, but myonecrotic activity was observed with both venoms of C. d. ru ruima. Among all antivenoms studied, the anti-bothropic-crotalic was t he best at neutralizing hemorrhagic and hemolytic activities. These re sults suggest that antivenom bothropic-crotalic should be used in the treatment of patients with snakebite by C. d. ruruima: besides its neu tralization on lethal activity, it also neutralizes the hemorrhagic ac tivity present in some venoms.