Radioimmunoreactive plasma bradykinin levels and histological changes during the course of cerulein-induced pancreatitis in rats.

The plasma bradykinin (BK) and serum amylase levels and histological changes in rats during the course of acute pancreatitis induced by a large dose of cerulein were examined. Animals were given four intraperitoneal injections of 20 micrograms/kg body wt of cerulein at hourly intervals. The plasma concentration of BK-like immunoreactivity (BK-LI), measured by a highly sensitive and specific radioimmunoassay established in this study, was found to reach a peak 6 h after the first injection of cerulein and then to remain elevated. On the other hand, the serum amylase and the histological alterations (i.e., interstitial edema, vacuolization, and inflammatory infiltration) were maximal 9 h after the first injection and returned to nearly normal after 24 h. These observations suggest that the BK generation is indicative of the participation of the kallikrein-kinin system in the pathophysiological change and that the plasma BK-LI level is a good marker of cellular damage and inflammation within the pancreas during the course of acute pancreatitis.