The role of nicotinic receptors in dog pancreatic exocrine secretion.

1 The effects of pentamethonium, an autonomic ganglion blocker, were studied on the exocrine pancreatic secretion of six conscious dogs given intravenous infusions of urecholine, caerulein or pentagastrin on a background of submaximal doses of secretin. 2 Urecholine-induced protein secretion was not affected but both caerulein- and to a smaller extent, pentagastrin-induced protein secretions were depressed by pentamethonium. 3 These results indicate that intravenous caerulein and pentagastrin, but not urecholine, act at least partially via nicotinic receptors. 4 Volume and bicarbonate output were depressed by pentamethonium when stimulated by intravenous caerulein with a background of secretin, but not when stimulated by pentagastrin on a background of secretin. 5 From these data it is suggested that caerulein and pentagastrin may potentiate secretin-stimulated hydrelatic secretion by different mechanisms.