Evidence for a cholinergic secretory innervation of the guinea-pig endometrium.

Uterine mucus secretion was studied by measuring carbohydrate release from everted guinea-pig uteri placed in organ baths. Field stimulation of the organ resulted in a significant increase in carbohydrate out-put, this increase was inhibited by tetrodotoxin, scopolamine and previous destruction of the paracervical ganglia. Previous section of the hypogastric nerve reduced the response to field stimulation, while interruption of the costouterine connexion or the pelvic nerve was without overt effect. Stimulation of the hypogastric nerve increased uterine carbohydrate secretion. Pelvic nerve stimulation produced no significant effect. Carbachol increased the carbohydrate secretion to the same extent as did field stimulation. Isoprenaline and methoxamine were without significant effect. It is suggested that certain endometrial cells have a cholinergic sympathetic secretory innervation with pre- and postganglionic fibers running in the hypogastric nerve.