The stimulation of canine prostatic secretion by sympathomimetic amines.

In unanesthetized, castrated, testosterone-treated dogs with surgically prepared fistulas which allowed the collection of prostatic fluid uncontaminated by urine, the s.c. administration of piocarpine hydrochloride, acetylcholine chloride, methacholine chloride and oxotremorine oxalate produced distinct secretory responses accompanied by parasympathomimetic effects such as salivation, reflex tachycardia and emesis. The i.v. administration, of relatively small doses of physostigmine and neostigmine similarly produced salivation but did not provoke prostatic secretion. Doses of these drugs sufficiently large to stimulate prostatic secretion also provoked more severe effects, the most notable being a transient prostration. it is concluded that the prostate gland of the dog is relatively more sensitive to direct-acting agents such as acetyicholine, methacholine and oxotremorine than to indirect-acting substances like physostigmine and neostigmine, and this conclusion is discussed in relation to present knowledge concerning the autonomic innervation of the prostate gland of the dog.