Iron, nitric oxide, and oxidative metabolism in Mya arenaria

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

Villa Carlos Paz

Otro; XLIV Reunión Anual SAIB; 2008

SAIB

The main objective of this work was to analyze Fe role and oxidative and nitrosative metabolism in Mya arenaria. M. arenaria samples were collected in the German Wadden Sea. The ratio Ascorbyl radical (A·)/ascorbate content (AH-) is understood as an index of oxidative stress. A· content, assessed by quantification of electronic paramagnetic resonance (EPR) signals, was 0.04±0.01 pmol/mg FW, and the AH- content 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. Total Fe content in M. arenaria was 1.9±0.7, 0.7±0.1 and 0.17±0.01 nmol/mg FW, in digestive glands (DG), mantle and gills, respectively. Labile Fe pool (LIP), assessed by EPR in DG, was 146±10 pmol/mg FW, and by employing calcein was 118±9 pmol/mg FW. The lipid radical content in the DG, assessed by EPR, was 27±1 pmol/mg FW, and the thiobarbituric reactive substances content amounted to 57±8 pmol/mg FW. The content of nitric oxide (NO) in DG was 99±3 pmol/mg FW. The generation rate of NO by nitric oxide synthase-like activity (assayed as NO production by EPR) was 3.16±0.06 pmol/mg FW DG/min. Further studies are required to analyze the effect of environmental stress conditions. The data presented here document the presence of highly reactive species in M. arenaria.