Physiological plasma concentrations of cholecystokinin stimulate pancreatic enzyme secretion and gallbladder contraction in man

Abstract

The present study was undertaken to determine whether infusion of cholecystokinin (CCK) to plasma concentrations comparable to those found after a meal stimulates pancreatic enzyme secretion and gallbladder contraction. Plasma CCK concentrations were measured by radioimmunoassay using antibody T204, which binds to all carboxyl-terminal CCK-peptides containing the sulfated tyrosine region. Ingestion of a standardized test meal in 7 normal subjects induced significant increases in plasma CCK from 2.0 ± 0.2 pmol/1 to levels between 4.6 ± 0.6 and 7.3 ± 1.0 pmol/1 (p<0.05−p<0.0005). Infusion of 2.5 pmol/kg.h CCK 33 resulted in significant increases in plasma CCK from 2.0 ± 0.2 to 3.9 ± 0.3 pmol/1 (p<0.0005). This infusion of CCK induced significant increases in trypsin secretion from 0.5 ± 0.1 to 1.4 ± 0.2 KU/15 min (p<0.005) and in bilirubin output from 1.6 ± 0.7 to 30.3 ± 8.0 μmol/15 min (p<0.05). It is concluded that physiological plasma concentrations of CCK stimulate pancreatic enzyme secretion and gallbladder contraction in man.