Effect of exogenous cholecystokinin and secretin on pancreatic secretion of insulin and glucagon in rats - In vivo model without hepatic filter

In order to study the effect of cholecystokinin and secretin on the endocri ne function of the pancreas, we have developed an experimental model that w e have applied to a total of 30 anesthetized rats stimulated with physiolog ical or supraphysiological doses of cholecystokinin and secretin administer ed intravenously by continuous infusion. Our results show that the serum in sulin concentration increases after the supramaximum dose of cholecystokini n is infused, while that of glucagon increases after the maximum dose of th is hormone. In case of secretin, the serum glucagon level increases after t he supramaximurn dose, while that of insulin is not affected by any dose. W e conclude that after infusion of physiological doses of cholecystokinin, t he pancreatic secretion of glucagon is modified but not that of insulin, wh ile secretin has no effect on the endocrine pancreatic secretion of either insulin or glucagon upon the same conditions.