title: Distribution of origin of nitric oxide synthase-immunoreactive nerve fibers in the rat epididymis.
abstract: Distribution of neuronal nitric oxide synthase-immunoreactive (nNOS-IR) nerve fibers and somata in the rat epididymis and major pelvic ganglia was studied by immunohistochemical methods. In the epididymis, the supply of nNOS-IR fibers was highest in the cauda and became progressively fewer toward the caput. In the cauda and corpus, nNOS-IR fibers were distributed throughout the subepithelial tissues and around the epithelial. The pattern of distribution of vasoactive intestinal polypeptide (VIP)- and tyrosine hydroxylase (TH)-immunoreactive fibers in the epididymis was similar but the latter was generally more numerous in a given region as compared to that of nNOS-IR fibers. A population of neurons in the major pelvic ganglia were nNOS-IR-, TH- or VIP-IR. Double-labeling studies revealed that few neurons in the major pelvic ganglia contained both nNOS-IR and TH-IR. Whereas nNOS-IR and VIP-IR appeared to co-localize in the same population of the pelvic ganglion cells. Similarly, nNOS-IR fibers in the epididymis were mostly VIP-positive and TH-negative. Unilateral injection of the fluorescent tracer Fluorogold into the junction between the vas deferens and the cauda labeled a population of neurons in the right and left major pelvic ganglia, some of which were also nNOS-IR. A small number of dorsal root ganglion cells contained Fluorogold and very few expressed NOS-IR. It may be concluded that nNOS-IR nerve fibers in the rat epididymis arise mainly from neurons in the major pelvic ganglia the major of which express VIP-IR but not TH-IR. The extensive supply of nNOS-immunoreactive fibers around the epithelium and throughout the subepithelial tissues suggests that NO may be closely associated with smooth muscle contraction.
authors.affiliation: Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43614, USA.
authors.forename: N J
authors.initials: NJ
authors.lastname: Dun
authors.forename: S L
authors.initials: SL
authors.lastname: Dun
authors.forename: R L
authors.initials: RL
authors.lastname: Huang
authors.forename: E C
authors.initials: EC
authors.lastname: Dun
authors.forename: C C
authors.initials: CC
authors.lastname: Lai
authors.forename: P Y
authors.initials: PY
authors.lastname: Wong
authors.forename: U
authors.initials: U
authors.lastname: Förstermann
mesh_terms: D000818:Animals; D004822:Epididymis / Q000201:enzymology*; D005456:Fluorescent Dyes; D005727:Ganglia, Spinal / Q000166:cytology / Q000201:enzymology; D007001:Hypogastric Plexus / Q000166:cytology / Q000201:enzymology; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000201:enzymology*; D009474:Neurons / Q000201:enzymology; D018377:Neurotransmitter Agents / Q000032:analysis*; D019001:Nitric Oxide Synthase / Q000032:analysis*; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D013266:Stilbamidines; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D005456:Fluorescent Dyes; D018377:Neurotransmitter Agents; D013266:Stilbamidines; D014660:Vasoactive Intestinal Peptide; D019001:Nitric Oxide Synthase; D014446:Tyrosine 3-Monooxygenase