Myotoxic activity of phospholipases A2 isolated from cobra venoms: neutralization by polyvalent antivenoms

Phospholipases A2 which produce myonecrosis when injected i.m. into mice were isolated from venoms of Naja nigricollis, N.h.haje and N.nivea by gel filtration, ion-exchange chromatography on SP-Sephadex C-25 and CM-cellulose and by hydrophobic interaction chromatography on Phenyl-Sepharose CL-4B. Basic polypeptides of the cardio/cytotoxin-type were essentially free of myotoxic activity. Polyvalent antivenoms were tested for their ability to neutralize the myotoxic activity of the phospholipases A2 when mixed with them prior to injection. Antivenoms from Behringwerke (Orient, Central Africa, North Africa) and from the South African Institute for Medical Research, but not habu (Trimeresurus flavoviridis) monovalent antivenom, neutralized the myotoxic activity of the phospholipases A2.