THE INTRAMURAL INNERVATION OF THE HUMAN VAS-DEFERENS AND SEMINAL-VESICLE IN INFANTS AND CHILDREN

Immunohistochemical methods were used to study the autonomic innervati on of the vas deferens and seminal vesicle in a series of human postna tal specimens ranging in age from 1 month to 3 years. The occurrence a nd distribution of nerves immunoreactive for the neuropeptides vasoact ive intestinal polypeptide (VIP), neuropeptide Y (NPY) substance P (SP ) and calcitonin gene-related peptide (CGRP) were investigated. In add ition immunoreactivity to tyrosine hydroxylase (TH), dopamine-beta-hyd roxylase (DBH) and to protein gene product (PGP 9.5), a general nerve marker were also studied. A neurohistochemical method was used to loca lise acetylcholinesterase. The results obtained from either organ were similar. Regardless of age, a rich plexus of nerve fibres immunoreact ive for PGP 9.5 was present both within the muscle coat and also benea th the epithelium of the vas deferens and seminal vesicle. Some acetyl cholinesterase containing nerves occurred in the muscle coat but the m ajority were found under the epithelium in the connective tissue of th e mucosa. TH and DBH-containing nerves (presumably noradrenergic in ty pe) formed dense intramuscular plexuses but none occurred subepithelia lly. In contrast NPY-containing nerves formed a less dense intramuscul ar plexus and were also observed beneath the epithelium. Thus while NP Y may occur in some of the intramuscular noradrenergic nerve fibres it is clearly not confined to this type of nerve in either the vas defer ens or the seminal vesicle. SP- and CGRP-containing nerves were extrem ely infrequent and, when observed, were confined to the muscle coat. V ery occasional varicose VIP-containing nerves were seen in the muscle coat but VIP was absent from the subepithelial nerve plexus, a finding in marked contrast to the situation in the adult vas deferens.