Use of the C-terminal octapeptide of cholecystokinin in clinical radiology. I. The gallbladder.

Two 30-min. infusion doses of the octapeptide of chloecystokinin (C8-CCK) (1 and 4 ng/kg/min) produced equal and consistent gallbladder contractions (75 +/- 8% mean and SEM decrease in size) in 24 human volunteers. The long 30-min infusion method of C8-CCK administration appears better than bolus injection (30 to 180 s) for cholecystokinetic cholecystography.