Inhibition of pancreatic secretion of enzymes by calcitonin.

Calcitonin in pharmacological dosage inhibits the secretion of enzymes in the human pancreas without influencing the production of fluid and bicarbonate. The degree of inhibition is the same in a juice stimulated by secretin alone and by secretin plus pancreozymin-cholecystokinin or caerulein. Thus the endogenous and the exogenously applied pancreozymin is inhibited in its action. The secretion of enzymes, which is induced cholinergically by carbamylcholine or insulin hypoglycemia, is not altered by calcitonin. The inhibitory action of CT is not counteracted by infusion of calcium thus showing that local depletion of calcium is not the mechanism of inhibition. Possible mechanisms are the direct interference with pancreozymin at the acinar cell and the inhibition of hormone-release from the pancreozyminproducing cells.