Inhibition of the stimulated exocrine pancreas by absorbed amino acids.

Intravenous infusion of amino acids is known to inhibit the stimulated pancreas and it has been suggested that this may act as a feedback mechanism in pancreatic regulation. To investigate this, chronic pancreatic fistula dogs were studied to determine if postprandial levels of hyperaminoacidemia inhibit the stimulated pancreas. Duplicate dose-response experiments using exogenous cholecystokinin (CCK) and intraduodenal amino acids were performed with and without a simultaneous intravenous infusion of mixed amino acids, which simulated postprandial hyperaminoacidemia. Significant (P less than 0.05), though minor, inhibition of pancreatic responses to both endogenous and exogenous CCK was noted with the simultaneous infusion of amino acids. It was concluded that, while amino acids may exert some inhibitory influence on pancreatic secretion after absorption, this is unlikely to be an important physiological mechanism.