Influence of cholinergic receptor blockade and stimulation on the anterior pituitary mitotic activity.

The effects of pilocarpine and atropine on the mitotic incidence in the anterior pituitary in male and ovariectomized estradiol-pretreated female rats was investigated. It was shown that pilocarpine stimulated, while atropine inhibited, the anterior pituitary mitotic activity. It was also shown that carbachol enhanced the mitotic incidence in the organ-cultured anterior pituitary and its effect was blocked by scopolamine. The existence of the muscarinic cholinergic receptor within the anterior pituitary, as well as its involvement in the control of the anterior pituitary mitotic activity, is suggested.