Phospholipase A2 in sodium taurocholate-induced experimental hemorrhagic pancreatitis in the rat

We investigated the concentration of immunoreactive pancreatic phospholipase A2 (pan-PLA2) and the catalytic activity of phospholipase A2 (CA-PLA2) in plasma, peritoneal fluid, and pancreas of rats in which acute hemorrhagic pancreatitis was induced by an intraductal injection of sodium taurocholate. The contribution of pancreas to the CA-PLA2 in plasma was studied by removing pancreatic PLA2 by absorbing plasma samples with a polyclonal antibody raised in a rabbit against rat pancreatic PLA2. Sodium taurocholate injected into the pancreatic duct produced hemorrhagic pancreatitis with necrosis and inflammatory cell invasion within 8 hr. Saline injection caused edematous pancreatitis, but sham operation did not alter pancreatic morphology from normal. The concentration of pan-PLA2 increased rapidly in plasma in all animals, but significantly more in sodium taurocholate-injected animals than in saline-injected or sham-operated animals. The level of CA-PLA2 in plasma increased in sodium taurocholate-injected animals only. There was no correlation between pan-PLA2 and CA-PLA2 values in plasma in sodium taurocholate-injected animals. The CA-PLA2 was marginally increased in pancreatic tissue of sodium taurocholate-injected animals compared to that of saline-injected and sham-operated animals at 8 hr. Treatment by the anti-pan-PLA2 antibody effectively removed pan-PLA2 from plasma and peritoneal fluid samples in sodium taurocholate-injected animals. The level of CA-PLA2 in plasma was similar before and after antibody treatment.(ABSTRACT TRUNCATED AT 250 WORDS)