The stimulation of canine prostatic secretion by pilocarpine.

The stimulation of prostatic secretion by pilocarpine was studied in unanesthetized, castrated, testosterone-treated dogs with surgically prepared fistulas which allowed the collection of prostatic fluid uncontaminated by urine. In these dogs the intravenous injection of pilocarpine stimulated prostatic secretion. Treatment of these dogs with atropine, hexamethonium or pronethalol decreased the volume of secretion. Treatment with Dibozane, phenoxybenzamine, reserpine, morphine or cocaine did not reduce the response. It is concluded that the stimulation of canine prostatic secretion by pilocarpine cannot be attributed entirely to a direct action upon the gland but must involve additional, indirect actions. The possibilities are discussed that pilocarpine might provoke prostatic secretion in part by liberating catecholamines which in turn stimulate secretion, in part by activating the preganglionic fibers to the sympathetic cholinergic secretory fibers innervating the gland, and in part by a direct action on the gland.