PLATELET-ACTIVATING-FACTOR MEDIATES PANCREATIC FUNCTION DERANGEMENT IN CERULEIN-INDUCED PANCREATITIS IN RATS

1. We have assessed the role of platelet-activating factor in caerulei n-induced acute pancreatitis (four subcutaneous injections of caerulei n at a dose of 20 mu g/kg) by measuring platelet-activating factor lev els in portal blood, pancreatic tissue and peritoneal exudate in rats with and without pancreatitis. 2. We have also observed the effect of the platelet-activating factor antagonist, BN-52021, on the hyperamyla saemia and exocrine pancreatic secretion impairment associated with pa ncreatitis. 3. In rats with pancreatitis the basal pancreatic flow rat e was increased (1.63 +/- 0.41 versus 0.25 +/- 0.03 mu l/min). Total p rotein output was similar in both untreated (5.98 +/- 1.93 mu g/min) a nd caerulein-injected (6.5 +/- 2.0 mu g/min) animals. Amylase output w as lower in rats with pancreatitis (19.6 +/- 4.8 mu-units/min) than in controls (39.4 +/- 16.6 mu-units/min). 4. Caerulein-treated animals h ad significantly higher serum amylase levels than untreated animals. B N-52021 significantly reduced the caerulein-induced hyperamylasaemia. 5. Portal blood platelet-activating factor levels increased in rats wi th pancreatitis and in rats infused with cholecystokinin. Rats injecte d with caerulein and BN-52021 had portal blood levels of platelet-acti vating factor that were lower than those with pancreatitis. 6. Morphol ogical derangements associated with pancreatitis (inflammatory infiltr ation and cell vacuolization) were also markedly reduced in BN-52021-t reated animals. 7. The results of this study suggest that platelet-act ivating factor is involved in the development of caerulein-induced acu te pancreatitis in rats.