The effects of gastrin, gastric inhibitory polypeptide, secretin, and the octapeptide of cholecystokinin upon immunoreactive somatostatin release by the perfused canine pancreas.

Abstract

A B S T R A C T The effects ofgastrin, gastric inhibitory polypeptide, secretin, and the octapeptide of pancre- ozymin-cholecystokinin on immunoreactive somatosta- tin release were studied in the isolated perfused dog pancreas. Gastrin at a concentration of 65 ng/ml and the octapeptide of pancreozymin-cholecystokinin at a c.oncentration of 25 ng/ml produced a prompt, but transient statistically significant, twofold rise in mean somatostatin concentration. Secretin at a concentration of 0.3 U/ml and gastric inhibitory polypeptide concentration of 58 ng/ml produced a prompt two-to threefold rise in mean somatostatin release, which persisted throughout the perfusion period. With all four polypeptides the pattern of the somatostatin re- sponse resembled that of insulin. It appears that pan- creatic somatostatin release is stimulated by gastro- intestinal hormones that influence the secretion of insulin and glucagon.