INNERVATION OF THE RABBIT DUCTUS DEFERENS AFTER VASECTOMY AND VASOVASOSTOMY

The urethral end of the ductus deferens in New Zealand white rabbits bilaterally vasectomized retained normal adrenergic innervation as evaluated by fibers identified with formalin-induced fluorescence. The testicular end of the ductus deferens and the caudal epididymal innervation were severely compromised. The site of the vascetomy may affect the degree of denervation in that inguinal vasectomies destroyed most, but not all, innervation, whereas vasectomies performed adjacent to the caudal epididymis (scrotal) caused total denervation. With vasovasostomy 30 days after vasectomy, significant reinnervation of the ductus deferens was observed by 28 days after the second operation. At the vasovasostomy site the nerve fibers were tortuously swirled and innervation was less than in the adjacent urethral and testicular sections of the ductus deferens. Such a zone may impede the flow of sperm during sexual excitement while not significantly affecting slow filling. Reinnervation of the caudal epididymis was slower and apparently less complete than that of the ductus deferens; by day 49 post vasovasostomy, only 20% of the normal innervation density was found.