Impaired gallbladder emptying is one of the various factors suggested to be involved in the pathogenesis of
gallstones. The present study was undertaken to determine whether gallbladder emptying, endogenous
cholecystokinin (CCK) secretion, or their interrelation is altered in patients with
gallstones. After intraduodenal administration of 60 ml
corn oil, plasma CCK concentration was measured by a sensitive and specific radioimmunoassay and gallbladder emptying by cholescintigraphy. Patients with
gallstones (N = 20) produced significantly less endogenous CCK (105 +/- 17 pmol/liter 60 min; P less than 0.001) than control subjects (191 +/- 11 pmol/liter 60 min, N = 20); gallbladder emptying in the patients was significantly decreased at 5, 10, 40, 45, and 50 min but the reduction in gallbladder emptying did not reach statistical significance at 60 min (patients 44 +/- 8%, control subjects 60 +/- 4%). In addition, the gallbladder responsiveness to
intravenous infusion of the synthetic CCK analog
cerulein was investigated. Based on the results of gallbladder emptying in response to endogenous and exogenous CCK, four subgroups of
gallstone patients were identified: (1) a group (N = 7) with normal gallbladder sensitivity to CCK, (2) a group (N = 6) with significantly increased gallbladder sensitivity to CCK, (3) a group (N = 6) with impaired gallbladder emptying after
corn oil due to a significantly reduced endogenous CCK secretion but with normal gallbladder sensitivity to CCK, and (4) one patient whose gallbladder was unresponsive to CCK and was found to have chronic
cholecystitis at surgery.