title: Formation of guanidinosuccinic acid, a stable nitric oxide mimic, from argininosuccinic acid and nitric oxide-derived free radicals.
abstract: Guanidinosuccinic acid (GSA) is noted for its nitric oxide (NO) mimicking actions such as vasodilatation and activation of the N-methyl-D-aspartate (NMDA) receptor. We have reported that GSA is the product of argininosuccinate (ASA) and some reactive oxygen species, mainly the hydroxyl radical. We tested for GSA synthesis in the presence of NO donors. ASA (1 mM) was incubated with NOR-2, NOC-7 or 3-morpholinosydomine hydrochloride (SIN-1) at 37 degrees C. GSA was determined by HPLC using a cationic resin for separation and phenanthrenequinone as an indicator. Neither NOR-2 or NOC-7 formed GSA. SIN-1, on the other hand, generates NO and the superoxide anion which, in turn, generated peroxynitrite which was then converted to the hydroxyl radical. Incubation of ASA with SIN-1 leads, via this route, to GSA. When ASA was incubated with 1 mM SIN-1, the amount of GSA produced depended on the incubation time and the concentration of ASA. Among the tested SIN-1 concentrations, from 0.5 to 5 mM, GSA synthesis was maximum at 0.5 mM and decreased with increasing concentrations of SIN-1. Carboxy-PTIO, a NO scavenger, completely inhibited GSA synthesis. SOD, a superoxide scavenger, decreased GSA synthesis by 20%, and catalase inhibited GSA synthesis only by 12%; DMSO, a hydroxyl radical scavenger completely inhibited GSA synthesis in the presence of SIN-1. These data suggest that the hydroxyl radical derived from a combination of NO and the superoxide anion generates GSA, a stable NO mimic. Meanwhile, synthesis of GSA by NO produces reactive oxygen and activates the NMDA receptor that generates NO from GSA, suggesting a positive feed back mechanism.
authors.affiliation: Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba-city, Ibaraki-Ken, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Aoyagi
authors.forename: K
authors.initials: K
authors.lastname: Akiyama
authors.forename: S
authors.initials: S
authors.lastname: Shahrzad
authors.forename: C
authors.initials: C
authors.lastname: Tomida
authors.forename: A
authors.initials: A
authors.lastname: Hirayama
authors.forename: S
authors.initials: S
authors.lastname: Nagase
authors.forename: K
authors.initials: K
authors.lastname: Takemura
authors.forename: A
authors.initials: A
authors.lastname: Koyama
authors.forename: S
authors.initials: S
authors.lastname: Ohba
authors.forename: M
authors.initials: M
authors.lastname: Narita
mesh_terms: D001125:Argininosuccinic Acid / Q000737:chemistry*; D001565:Benzoates / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005246:Feedback; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals; D006146:Guanidines / Q000138:chemical synthesis*; D006834:Hydrazines / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000737:chemistry; D007093:Imidazoles / Q000494:pharmacology; D008981:Molsidomine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D009566:Nitrates / Q000737:chemistry; D009569:Nitric Oxide / Q000819:agonists* / Q000737:chemistry; D020030:Nitric Oxide Donors / Q000494:pharmacology; D017382:Reactive Oxygen Species; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013386:Succinates / Q000138:chemical synthesis*; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: C115239:3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-propanamine; D001565:Benzoates; D016166:Free Radical Scavengers; D005609:Free Radicals; D006146:Guanidines; D006834:Hydrazines; D007093:Imidazoles; D009566:Nitrates; D020030:Nitric Oxide Donors; D017382:Reactive Oxygen Species; D016194:Receptors, N-Methyl-D-Aspartate; D013386:Succinates; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D001125:Argininosuccinic Acid; C039642:peroxynitric acid; D009569:Nitric Oxide; D017665:Hydroxyl Radical; C002385:linsidomine; C001318:guanidinosuccinic acid; D008981:Molsidomine; D013482:Superoxide Dismutase; D004121:Dimethyl Sulfoxide