title: Analysis of neuronal nitric oxide synthase isoform expression and identification of human nNOS-mu.
abstract: The neuronal form of nitric oxide synthase (nNOS) is responsible for the production of NO, which acts as a neurotransmitter for penile erection and urethra relaxation. An nNOS splice variant form, nNOS-mu, was first reported to be specifically expressed in skeletal muscle and heart in the rat, but later also identified in rat penile cavernosum. We report here an apparently universal expression of nNOS-mu mRNA in rat tissues, including brain, which was previously reported to be lacking nNOS-mu. Immunoblot analysis revealed that some commercially available nNOS antibodies had high levels of nonspecific activities, which could lead to the appearance of seemingly multiple forms of nNOS. Immunohistochemical analysis with these antibodies also produced nonspecific stainings. In humans, nNOS-mu; expression appeared to be confined to skeletal muscle and heart. Human penile tissues obtained from patients with erectile dysfunction did not express nNOS-mu. The human nNOS-mu-specific cDNA sequence was 89% homologous to its rat counterpart.
authors.affiliation: Department of Urology, University of California, San Francisco 94143, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Lin
authors.forename: A
authors.initials: A
authors.lastname: Lau
authors.forename: E
authors.initials: E
authors.lastname: Bakircioglu
authors.forename: R
authors.initials: R
authors.lastname: Tu
authors.forename: F
authors.initials: F
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Week
authors.forename: L
authors.initials: L
authors.lastname: Nunes
authors.forename: T F
authors.initials: TF
authors.lastname: Lue
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D052248:Nitric Oxide Synthase Type I; D009928:Organ Specificity / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017386:Sequence Homology, Amino Acid
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat