SECRETORY RESPONSES OF EXTRAMEDULLARY CHROMAFFIN TISSUE.

When the isolated inferior mesenteric ganglion of the dog was perfused with Locke solution, the effluent fluid contained noradrenaline and adrenaline. At rest the output of noradrenaline ranged from 0.7 to 40 ng/min, and that of adrenaline from 0.7 to 25 ng/min. Electrical stimulation of the inferior splanchnic nerves did not alter the catechol amine content of the perfusate, and stimulation of the ascending mesenteric nerves caused an increase to little more than twice the resting value. When acetylcholine or dimethylphenyl-piperazinium iodide was infused into the preparation, the catechol amine content of the effluent fluid was 6- to 100-times the resting level. Two drugs with muscarinic action (pilocarpine and 3-acetoxy-1-benzyl-1-methylpyrrolidinium bromide) produced only very small increases in catechol amine release. Angiotensin, in doses ranging from 20 ng to 2 mug, inhibited release of catechol amines, and bradykinin had a weak stimulatory effect. It is suggested that the catechol amines released into the effluent fluid were derived from chromaffin tissue in the ganglion; evidence for innervation of this tissue was unobtainable, but its catechol amines were readily released by the injection of nicotinic drugs.