title: Type I nitric oxide synthase fully accounts for NADPH-diaphorase in rat striatum, but not cortex.
abstract: The novel gaseous neuromediator nitric oxide is thought to play an important role in development and plasticity. Despite this, gene-knockout mice lacking neuronal (Type I) nitric oxide synthase exhibit relatively normal brain development and behavior. The nervous system of these mice (especially the forebrain) retains some calcium-dependent nitric oxide synthesis, presumably reflecting other isozymes. Type I nitric oxide synthase has NADPH-dependent diaphorase activity. However, this stain also recognizes other isozymes, and it remains controversial whether all diaphorase-positive neurons contain Type I nitric oxide synthase. To assess whether neurons containing another isoform of nitric oxide synthase may be present in the forebrain of normal rodents, we studied co-localization of diaphorase staining with immunocytochemistry for Type I nitric oxide synthase. Co-localization was complete in the striatum, but some neurons deep in cortex were diaphorase-positive and immunonegative, and therefore may contain a splice variant or novel isozyme of nitric oxide synthase.
authors.affiliation: Department of Cell Biology & Anatomy, University of North Carolina, Chapel Hill 27599.
authors.forename: V N
authors.initials: VN
authors.lastname: Kharazia
authors.forename: H H
authors.initials: HH
authors.lastname: Schmidt
authors.forename: R J
authors.initials: RJ
authors.lastname: Weinberg
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D003342:Corpus Striatum / Q000166:cytology / Q000378:metabolism*; D006651:Histocytochemistry; D007150:Immunohistochemistry / Q000379:methods; D007527:Isoenzymes / Q000378:metabolism*; D051379:Mice; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D019001:Nitric Oxide Synthase; D051381:Rats; D013194:Staining and Labeling; D014018:Tissue Distribution
chemical_list: D007527:Isoenzymes; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase