Interaction of neurotensin, cholecystokinin, and secretin in the stimulation of the exocrine pancreas in the dog.

The effects of exogenous neurotensin, secretin, and cholecystokinin-33 alone and in combination on pancreatic secretion were investigated in dogs prepared with pancreatic fistulae. Neurotensin infused intravenously caused a dose-dependent stimulation of exocrine pancreatic secretion. Increasing doses of neurotensin combined with a constant small dose of secretin potentiated pancreatic output of protein and had a tendency to reduce secretion of the bicarbonate. Increasing doses of neurotensin combined with a constant small dose of cholecystokinin-33 potentiated pancreatic output of bicarbonate and lead to a reduction (insignificant) of pancreatic protein secretion. These observations suggest an interaction of neurotensin with pancreatic receptors for secretin and cholecystokinin.