Effect of neurotensin on exocrine pancreatic secretion in dogs.

The effects of various doses of synthetic neurotensin on exocrine pancreatic secretion were investigated in dogs prepared with pancreatic fistulae. Increasing doses of neurotensin infused intravenously caused a dose-dependent stimulation of exocrine pancreatic secretion. Plasma neurotensin levels determined with a radioimmunoassay kit for neurotensin were significantly correlated to the amount of neurotensin infused. Significant stimulation of exocrine pancreatic secretion was observed when 2.5 pmol kg-1 min-1 neurotensin were infused. This dose resulted in neurotensin plasma levels comparable to those observed after a meal. Combined infusions of neurotensin and the cholecystokinin analogue cerulein had synergistic effects on pancreatic bicarbonate output and raised the HCO-3:protein ratio. These observations suggest that neurotensin may play a role in the early phase of postprandial stimulation of exocrine pancreatic function.