The serum complement system--a mediator of acute pancreatitis.

The role of the complement system in the initial membrane lesion of acute pancreatitis was investigated. In the experimental sodium-taurocholate pancreatitis of the rat a sudden and steady decline of serum complement was observed. The deposition of C3 component of complement in acute pancreatitis could be demonstrated by immunofluorescence. To rule out mere deposition or activation of complement in the interstitial exsudative fluid, single acinar cells of rat and rabbit pancreatic tissue were prepared and transfered to culture medium. In contrast to heat inactivated serum and C6 deficient serum these cells were lysed by trypsin activated fresh serum. Consequently, an acute pancreatitis could be induced by activating exclusively the complement system by injection of cobra venom factor into the pancreatic duct of rats. The activated complement system is thought to be responsible for initial membrane lesion in exsudative inflammation, as could be shown in acute pancreatitis.