Exposure to excess of iron in vivo affects oxidative status in the bivalve Mya arenaria

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

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY.

ELSEVIER INC

Lugar: Oxford; Año: 2010 vol. 152 p. 167 - 174

0742-8413

The effect of in vivo Fe exposure on the oxidative metabolism of the bivalve Mya arenaria was studied. Fe wassupplemented in natural seawater and resulted in a significant increase in the total Fe content in the bivalvedigestive gland (DG) between 9 to 17 days of exposure. Mortality of treated animals increased drasticallyafter day 18. Oxidative stress conditions were characterized in DG through assessment of the generation ofreactive oxygen species (ROS) and ascorbyl radical (A) content. Both parameters were affected following abiphasic profile showing significant increases by days 2 and 9 of Fe exposure. The content of 2-thiobarbituricacid reactive substances (TBARS) was significantly increased over control values by days 2, 9 and 17 oftreatment. The labile Fe pool (LIP) in isolated DG was elevated over control values by day 7, and maintainedthis increase until day 17 of Fe exposure. The content of NO, assessed by EPR spin trapping, was 60% lower inDG of animals exposed for 2 days to Fe than in control values, with no further changes. The biphasic profile ofoxidative stress response to Fe exposure in DG suggests that at early stages of Fe supplementation thecellular control mechanisms, such as CAT activity, were operative to limit oxidative damage, but further Feexposure overwhelmed these abilities. Moreover, the second phase could be understood as the consequenceof the exhaustion of cellular protective systems that could also involve NO.