Studies on the site of action of neurotropin in experiments on denervation-supersensitivity of the duodenum and vas deferens of rats and mice.

In order to clarify to a greater extent its action on peripheral nerves, various experiments were conducted using denervated animals to determine the effects of the nervous sedative, Neurotropin (NSP, containing many types of polysaccharides), on the site considered to be the periphery of autonomic nerves and the central nervous system. The increase in response to ACh due to bilateral cardiac vagotomy was significantly inhibited by a daily administration of NSP, but the increase in the response to noradrenaline (NA) due to celiac sympathectomy was hardly affected by this administration. The supersensitivity to the muscarinic action of ACh or methacholine of a denervated rat vas deferens, owing to ablation of the serous membrane, was significantly inhibited by the daily administrations of NSP. However, supersensitivity to NA was hardly affected. NSP never had any effect on the increase in the NA response of the duodenum and vas deferens isolated from mice given 6-hydroxydopamine, an adrenergic degenerator. Thus, an inhibitory action of NSP on denervation-supersensitivity is conceivably exerted on the parasympathetic nerves, rather than on the sympathetic nerves, and on a muscarinic receptor site, instead of a nicotinic site.