title: Immunocytochemical distribution of nitric oxide synthase in the human seminal vesicle: a light and electron microscopical study.
abstract: Although nitric oxide (NO) has been proven to be one of the most important non-adrenergic, non-cholinergic mediators in the control of human reproductive tract organs, to date information on the significance of NO-mediated signal transduction in the control of human seminal vesicle (SV) function is still sparse.()Recent investigations have underlined the significance of NO in the maintenance of sperm capacitation and viscosity of the seminal plasma as well as in the control of mammalian seminal vesicle smooth muscle tone. In order to further investigate the functional impact of NO on the regulation of normal SV function, we examined the distribution of NADPH-diaphorase (NADPH-d), endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) in the cellular anatomy of human SV by means of light and electron microscopical immunocytochemistry (LM, EM) in combination with the tyramide signal amplification technique. Human SV were obtained from 15 patients who had undergone surgery for pelvic malignancies (carcinoma of the prostate or urinary bladder). SV specimens were fixed, sectioned and examined by LM and EM for the presence of NAPDH-d, eNOS and nNOS using specific antibodies and advanced staining procedures. LM revealed a dense NADPH-d reaction in glandular epithelial structures, whereas no substantial labeling was detected in the fibromuscular stroma. EM showed that the NADPH-d reaction product was abundantly detectable attached to membranes of the endoplasmic reticulum, mitochondria and the nuclei of glandular epithelial cells. nNOS staining was found in nerve fibers branching within the SV tissue. eNOS staining was present in small vessels but was only observed to a minor degree in glandular and subglandular structures and the smooth muscle stroma. Our results support the hypothesis that human SV is a site of NO production. The distribution of NADPH-d may give rise to the speculation that NO is mainly involved in the regulation of SV secretory activity. The sparse correlation between NADPH-d-, eNOS- and nNOS-staining might hint at the existence of a previously unidentified NOS isoform in human SV.
authors.affiliation: Hannover Medical School, Department of Urology, 30625 Hannover, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Uckert
authors.forename: Andreas
authors.initials: A
authors.lastname: Stanarius
authors.forename: Christian G
authors.initials: CG
authors.lastname: Stief
authors.forename: Gerald
authors.initials: G
authors.lastname: Wolf
authors.forename: Udo
authors.initials: U
authors.lastname: Jonas
authors.forename: Stefan
authors.initials: S
authors.lastname: Machtens
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; D012669:Seminal Vesicles / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: C496320:NOS1 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; D009252:NADPH Dehydrogenase