title: Nitric oxide synthase in the brain: light and electron microscopical findings based on the NADPH-diaphorase reaction.
abstract: The recent discovery of the identify of nitric oxide synthase with the reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) has powerfully stimulated the anatomical localization of sites of nitric oxide synthesis in the nervous system. In the present study the widely used light microscopical technique for NADPH-d staining was adapted to the electron microscopical level by applying the tetrazolium salt 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl)tetrazolium chloride (BSPT) which produces an electron-dense reaction product, BSPT-formazan. Predominantly membranes of the endoplasmic reticulum were stained. Apart from singular heavily labeled neurons, a majority of nerve cells, light microscopically "unstained", shows sporadically formazan deposits, and, likewise, but regionally different, a few astroglial cells. Lesions induced by the glutamate agonists quinolinic acid and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) display surviving neurons, which are predominantly stained for NADPH-d. Astroglial cells within lesioned areas exhibit increased amounts of reaction product, apparently as a consequence of enzyme induction.
authors.affiliation: Institute of Medical Neurobiology, Faculty of Medicine, University of Magdeburg, Federal Republic of Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wolf
authors.forename: S
authors.initials: S
authors.lastname: Würdig
authors.forename: G
authors.initials: G
authors.lastname: Henschke
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009336:Necrosis; D019001:Nitric Oxide Synthase; D017378:Quinolinic Acid / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D014018:Tissue Distribution; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase; D017378:Quinolinic Acid