MAXIMAL SECRETORY CAPACITY OF THE CANINE PANCREAS IN RESPONSE TO PANCREOZYMIN AND SECRETIN.

The output of amylase in nine dogs with chronic pancreatic fistulae has been studied in response to continuous infusions and single intravenous injections of pancreozymin and dose-response curves obtained. A maximal secretory response was reached by each form of administration of the hormone, supramaximal doses giving no further increase. By combining the maximal pancreozymin dose with a maximal secretin dose in a single injection, the maximal amylase, fluid, and bicarbonate secretory capacity of the dog pancreas was determined. On the average, maximal response to pancreozymin was obtained with 0.5–2.0 U/kg min given as a continuous infusion, with 10–25 U/kg as a single injection, and with a dose of 5–15 U/kg when combined with 8 U/kg secretin (maximal dose). In all experiments variability was least at maximal doses. With the combined pancreozymin-secretin injection the mean maximal 15-min output of fluid was 25.7 ml, of amylase 364 U, and of bicarbonate 3.15 mEq.