Abstract
Intraduodenal bile affects cholecystokinin (CCK) release and pancreatic exocrine secretion in rats, but the effects of intraduodenal bile on CCK release have not yet been well documented in humans. Patients with obstructive jaundice treated with external biliary drainage are a suitable model to determine whether or not CCK release is mediated by bile in humans. Nonspecific interference is observed in radioimmunoassay (RIA) for CCK in plasma. A highly sensitive RIA for the detection of CCK in blood using anti-CCK-8 N-terminus antibody (OAL-656) was developed by extraction of CCK from plasma using a Sep-Pak C18 cartridge. Using this RIA, the modulating role of intraduodenal bile in the regulation of blood CCK release was investigated in ten patients with obstructive jaundice due to cholangioma under management by external biliary drainage (PTCD, ENBD) . Fasting blood CCK levels in the patients after external drainage persisted at a significantly higher level than those in control subjects. Before drainage, administration of a test meal caused a high CCK response, and a high blood CCK concentration was persistently observed. After external drainage, the CCK response to the test meal was significantly lower than before drainage, but the blood CCK concentration was significantly higher compared with control subjects after 20 minutes. These results suggests that intraduodenal bile plays an important modulating role in CCK release in humans.
