Atropine depresses release of neurotensin and its effect on the exocrine pancreas.

In this study the effect of 10 and 20 micrograms . kg-1 . h-1 atropine sulfate on release and pancreatic effects of neurotensin was studied in 4 dogs. Neurotensin plasma levels rose significantly when a liquid fat preparation was infused intraduodenally. This rise was almost completely abolished by simultaneous infusion of atropine. Atropine further suppressed basal and fat-stimulated output of pancreatic volume, protein, and bicarbonate; it also reduced pancreatic secretion stimulated by an intravenous infusion of low doses (2.5 to 20 pmol . kg-1 . min-1) neurotensin. The effect of higher doses (80 and 240 pmol . kg-1 . min-1 of neurotensin was less affected. As neurotensin plasma levels in contrast to normal oral feeding did not rise after sham feeding, our findings suggest that release and action of neurotensin may at least in part be dependent on a cholinergic, non-cephalic mechanism.