NITRIC-OXIDE SYNTHASE AND TYROSINE-HYDROXYLASE ARE COLOCALIZED IN NERVES SUPPLYING THE POSTNATAL HUMAN MALE GENITOURINARY ORGANS

Purpose: The objective of this study was to examine the distribution o f nitric oxide synthase (NOS) and the catecholamine-synthesizing enzym e tyrosine hydroxylase (TH) in nerve fibers supplying the human neonat al male genitourinary organs. Materials and Methods: An indirect doubl e label immunofluorescence technique was employed on specimens obtaine d from infants and children at postmortem examination. Results: Many n erve fibers immunoreactive for both NOS and TH were observed in the mu scle coat of the vas deferens and the seminal vesicle, within the fibr omuscular stroma of the prostate gland and at the bladder neck, and al so-formed perivascular plexuses in each of these organs. Double-labele d nerves occurred less frequently in the intramural ureters and superf icial trigone while similar nerves in the bladder body were relatively sparse. Numerous nerves immunoreactive for NOS but not TH were observ ed at the base of the epithelium of each organ examined. Four types of autonomic ganglion cell were observed in nearby pelvic ganglia: those which contained NOS and TH, those which contained NOS alone, those wh ich contained TH alone and those which contained neither NOS nor TH. C onclusion: The results indicate that many of the noradrenergic nerves as well as nonnoradrenergic nerves supplying the male genitourinary or gans have the capacity to synthesize nitric oxide (NO) and that NO may play a significant role in the autonomic control of both the urinary and genital organs in the postnatal human male.