Serum and ascitic phospholipase A₂ activities and their heat stabilities in taurocholate induced rat acute pancreatitis

Abstract

Serum and ascitic phospholipase A₂ (PLA₂) activities in rat acute pancreatitis induced by sodium taurocholate (TCA) were investigated with special reference to their heat stabilities and were compared to those in serum of carrageenan induced granuloma in rats.
PLA₂ activity was measured by previously reported radiochemical method and was separated into two forms, heat stable and labile PLA₂, based on the stability to preincubation at 55°C for 5 minutes. While a heat stable PLA₂ predominantly increased in ascitic fluid, the elevations of both heat stable and labile PLA₂ activities in serum were observed in TCA induced pancreatitis.
On the other hand, serum PLA₂, which was mainly composed of heat labile form, elevated with the increase of leukocyte count in carrageenan induced granuloma rats.
These facts suggested that serum PLA₂ activity might increase in acute inflammatory changes other than in pancretic diseases. And it is assumed that PLA₂ derived from extrapancreatic origins as well as pancreatic secretory PLA₂ may also contribute to high PLA₂ level in acute pancreatitis, because pancreatic secretory PLA₂ was generally accepted to be heat stable.