CHEMICAL AND HISTOCHEMICAL STUDIES ON THE SYMPATHETIC INNERVATION OF THE VAS DEFERENS AND SEMINAL VESICLE OF THE GUINEA PIG

¹ Department of Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, New York

Postganglionic sympathetic nerves innervating the vas deferens and seminal vesicle appeared to originate from the hypogastric plexus. Identification of this plexus was achieved by the combined use of fluorescence histochemistry and denervation studies. The hypogastric plexus showed several clusters of ganglion cells with typical fluorescence, and many of these cells contained two to three nuclei. The plexus was situated at a distance of about 0.5 cm from the vas deferena, 0.3 cm from the seminal vesicle and 1.5 cm from the junction of vasa deferentia and seminal vesicles. Ligation of the short postganglionic fibers originating from the hypogastric plexus within one to two weeks reduced the norepinephrine content of the vas deferens to 0.42 µg/g, compared to a contralateral control value of 17.6 µg/g, and that of the seminal vesicle to 1.2 µg/g compared to a contralateral control value of 7.2 µg/g of tissue. The epididymal and terminal portions of the vas deferens and seminal vesicle, respectively, were effectively denervated by the ligation, whereas the prostatic portions were not. Fluorescence microscopy of the denervated portions also showed complete disappearance of fluorescent nerve terminals. The success of denervation was also ascertained by demonstrating the lack of uptake of ³H-norepinephrine in the denervated tissues and a marked sensitization of the denervated vas deferena to exogenous norepinephrine. On the basis of the above information, a schema of the postganghionic sympathetic innervation of vasa deferentia and seminal vesicles has been presented.