COLOCALIZATION OF NITRIC-OXIDE SYNTHASE, NEUROPEPTIDES AND TYROSINE-HYDROXYLASE IN NERVES SUPPLYING THE HUMAN POSTNATAL VAS-DEFERENS AND SEMINAL-VESICLE

Objective To determine the distribution and patterns of co-localizatio n of nitric oxide synthase (NOS), neuropeptides and tyrosine hydroxyla se (TH) in intrinsic nerves of the human post-natal vas deferens and s eminal vesicle. Materials and methods Double and triple immunolabellin g methods were used in tissue from 10 male infants and children (age r ange 2 months to 3 years) obtained at post-mortem examinations carried out within 12 h of death. Results Most nerves supplying the muscle co at of either organ were TH-immunoreactive (-IR), most of which also co ntained neuropeptide Y (NPY) while a smaller proportion contained both NPY and NOS, Minor populations of the TH/NPY-IR intramuscular nerves contained calcitonin gene-related peptide (CGRP), galanin (GAL), met-e nkephalin (m-ENK) or vasoactive intestinal polypeptide (VIP). Non-TH-I R intramuscular nerves were relatively infrequent and most contained N PY and either VIP or NOS. Presumptive secretomotor nerves formed subep ithelial plexuses in both organs, most of which contained NPY co-local ized with either VIP or NOS, with minor populations containing CGRP an d/or GAL. TH- and substance P (SP) -IR nerves were not observed subepi thelially. Perivascular nerve plexuses were mainly formed by TH-IR var icose nerves, most of which contained co-localized NPY and CGRP, with a smaller proportion containing NPY and NOS and minor populations cont aining VIP, m-ENK, SP or GAL. Conclusion These results indicate that t he autonomic control of the human vas deferens and seminal vesicle is provided by several immunohistochemically distinct nerve populations. Furthermore, NOS is present in a proportion of both the noradrenergic and nonnoradrenergic nerves. Pharmacological studies are now required to elucidate the precise roles of nitric oxide and neuropeptides in th e functional control of these organs.