Similar modes of action of calcitonin and glucagon in inhibiting pancreatic enzyme secretion in man

Abstract

The inhibitory action of both calcitonin (CT) and glucagon (GK) on human pancreatic secretion has been evaluated in detail. The reduction of enzyme secretion expressed as percentage corresponded to 60--80% of the initial values in response to both CT and GK when the hormones were given as single infusions during background stimulation with secretin or with secretin plus cholecystokinin-pancreozymin (CCK-PZ). After withdrawal of GK-infusion the return to normal values of enzyme secretion was distinctly faster than after CT, thus reflecting a more rapid degradation of circulating GK than of CT. In the presence of stimulation with secretin plus CCK-PZ, the combined administration of CT and GK did not enhance the inhibitory actions of CT and GK. Fluid and bicarbonate secretions were not affected by either CT or GK. The results suggest that CT and GK inhibit human pancreatic enzyme secretion by similar modes of action. Therefore, the combined administration of both CT and GK does not offer a reasonable approach to the treatment of acute pancreatitis.