Iron and radical content in Mya arenaria. Possible sources of NO generation

GONZÁLEZ, P.M.; ABELE, D. Y PUNTARULO, S.

AQUATIC TOXICOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2008 vol. 89 p. 122 - 128

0166-445X

The objective of this work was to analyze oxidative metabolism in Mya arenaria. Total Fe content in M. arenaria collected in the GermanWadden Seawas 1.9±0.7, 0.7±0.1 and 0.17±0.01 nmol/mg freshweight (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/mgFW, and the ascorbate content (AH-) was 478±12 pmol/mg FW. The ratio A/AH- was (8±1)×10-5 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.