Induction of myonecrosis by phospholipase a 2 from habu trimeresurus flavoviridis venom
Kihara, H.; Terashi S I.; Ohno, M.; Hashimura, S.
Snake 18(2): 84-91
Phospholipase A2 (PLA2) isolated from the venom of Trimeresurus flavoviridis (Habu) led to an increase in plasma creatine kinase (CK) levels as well as to cause myonecrosis at the site of injection in rabbits and rats. The CK activity in the plasma increased linearly with time after injection of the crude venom or PLA2. The increase in CK level was more remarkable with PLA2 than with the crude venom at a low dose, whereas no significant difference between two was observed at a high dose, showing the maximum rate in CK release. PLA2 derivatives with a little or no enzymatic activity, which were prepared by chemical modification of the active site histidine residue with p-bromophenacyl bromide or by chemical cleavage of the N-terminal octapeptide with cyanogen bromide, failed to elevate the CK level. The enzymatic activity of PLA2 is thus essential for increasing the CK level. T. flavoviridis antivenom prevented myonecrosis but not the increase in CK level by PLA2. It is likely that an increase in CK level is a necessary but not a sufficient condition for the assay of myonecrosis. PLA2 seems to be a factor to induce myonecrosis.