High plasma cholecystokinin levels in patients with chronic pancreatitis having abdominal pain.

Plasma cholecystokinin (CCK) responses after ingestion of a test meal in patients with mild chronic pancreatitis having abdominal pain were studied with a radioimmunoassay using the CCK specific antiserum (OAL-656) produced by a novel immunization procedure. Mean concentration of the fasting plasma CCK determined using CCK-8 as a standard was 31.5 +/- 5.8 pg/ml in six patients who had mild impaired exocrine function with pain, and was significantly higher than 10 healthy subjects (9.8 +/- 1.8 pg/ml). In those patients, the ingestion of a liquid test meal led to a peak of 75.1 +/- 25.4 pg/ml at 30 min, and the 120-min integrated CCK response (5427 +/- 1217.3 pg X min/ml) was significantly higher than in healthy subjects (1538 +/- 110.1 pg X min/ml).