title: Iron and radical content in Mya arenaria. Possible sources of NO generation.
abstract: The objective of this work was to analyze oxidative metabolism in Mya arenaria. Total Fe content in M. arenaria collected in the German Wadden Sea was 1.9+/-0.7, 0.7+/-0.1 and 0.17+/-0.01 nmol/mg fresh weight (FW), in digestive glands (DG), mantle and gills, respectively. Labile Fe pool, assessed by electronic paramagnetic resonance (EPR), was 146+/-10 pmol/mg FW, and by the fluorescence method employing calcein it was 118+/-9 pmol/mg FW. The lipid radical content in the DG, assessed by EPR, was 27+/-7 pmol/mg FW, and the thiobarbituric reactive substances content amounted to 57+/-8 pmol/mg FW. Ascorbyl radical (A) content, assessed by quantification of EPR signals, was 0.04+/-0.01 pmol/mg FW, and the ascorbate content (AH(-)) was 478+/-12 pmol/mg FW. The ratio A/AH(-) was (8+/-1)x10(-5)AU, suggesting a minimum oxidative stress even under physiological conditions, presumably depending on basal metabolic functions. The content of nitric oxide (NO), assessed by EPR, was 99+/-3 pmol/mg FW. The generation rate of NO by nitric oxide synthase-like activity (NOS-like) was assayed as NO production detected by EPR in the presence of l-arginine and NADPH, and was 3.16+/-0.06 pmol/(mg FW min). The data presented here document the detectable presence of highly reactive species in M. arenaria.
authors.affiliation: Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956, 1113 Buenos Aires, Argentina.
authors.forename: Paula Mariela
authors.initials: PM
authors.lastname: González
authors.forename: Doris
authors.initials: D
authors.lastname: Abele
authors.forename: Susana
authors.initials: S
authors.lastname: Puntarulo
mesh_terms: D000818:Animals; D004064:Digestive System / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D049892:Mya / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D018384:Oxidative Stress; D013379:Substrate Specificity; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D005609:Free Radicals; D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; D007501:Iron; D019001:Nitric Oxide Synthase