Treatment of guinea pig lymphocytes with Clostridium perfringens phospholipase C but not with Naja naja snake venom phospholipase A2 increased ornithine decarboxylase activity. The increase in ornithine decarboxylase activity was suppressed by actinomycin D or cycloheximide, suggesting that de novo syntheses of RNA and protein are necessary for the increase in the enzyme activity. These results suggest that the activation of phospholipase C rather than that of phospholipase A2 is responsible for induction of ornithine decarboxylase during lymphocyte transformation.
