Comparison of the biological activities in venoms from three subspecies ofthe South American rattlesnake (Crotalus durissus terrificus, C-durissus cascavella and C-durissus collilineatus)

The subspecies of the South American rattlesnake, Crotalus durissus, are cl assified according to their external morphological features and geographica l distribution. We have determined some biological activities of C. durissu s cascavella, C. durissus collilineatus and C. durissus terrificus venoms. C. durissus terrificus had a significantly higher clotting activity on bovi ne plasma and fibrinogen, human fibrinogen and rabbit plasma. C. durissus c ascavella presented a statistically higher phospholipase A(2) (PLA(2)) acti vity in regard to C. durissus collilineatus. Their myotoxic and proteolytic activity, median lethal doses, or median platelet aggregating doses (on ra bbit and human platelets) could not differentiate the three subspecies exam ined. However, the electrophoretic profile and the dose-response curve for edematogenic activity for C.d. cascavella venom were different from the oth ers. With regard to the inorganic element content of the venoms, higher lev els of Br, Cl and Mg, and a lower level of Zn, were found in C.d. cascavell a venom. Crotamine-like activity could not be detected in C.d. cascavella v enom. Furthermore, equine antivenom specific for C. durissus terrificus ven om cross-reacted equally with the antigens of the three venom pools by ELIS A and Western blotting. These results indicate that the venoms from the thr ee studied subspecies of C. durissus were very similar, except for minor di fferences in paw edema-inducing activity, electrophoretic profile, phosphol ipase A(2) activity, crotamine-like activity and inorganic element contents of C.d. cascavella venom. (C) 1999 Elsevier Science Inc. All rights reserv ed.