Effect of Sulfation of CCK-8 on Its Stimulation of the Endocrine and Exocrine Secretion from the Isolated Perfused Porcine Pancreas

Abstract

The secretory effect of sulfated and nonsulfated cholecystokinin octapeptide (CCK-8) was studied on the isolated perfused porcine pancreas. Both CCKs in concentrations from 10^–11 to 10^–8 mol/l in the presence of glucose (7.5, 5.0 or 3.5 mmol/l) were without effect on insulin and glucagon release. The exocrine secretion was stimulated by both CCKs in a dose-dependent manner, but sulfated CCK-8 was considerabley more potent. The study shows that CCK-8, a major constituent of endogenous CCK, does not contribute to the incretin mechanism, irrespective of degree of sulfation. In contrast, CCK-8 is a potent stimulator of exocrine pancreatic secretion. For this effect sulfation is crucial.