کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2603245 | 1133813 | 2010 | 10 صفحه PDF | دانلود رایگان |
This study investigated whether mercury (Hg) oxidative and genotoxic effects are related with its ability to inhibit selenium-dependent glutathione peroxidase (Se-GPx) activity in haemocytes of mussel Mytilus galloprovincialis. Se-GPx activity was measured both in Se-free cells’ cytosolic fraction and in Se-treated cells, pre-treated with 4 μg/l of Se (as sodium selenite), before the exposure to the metal. Hg at concentrations ranged within 10 or 20 μg/l, thus representing the onset of Hg toxic effects, showed to inhibit Se-GPx activity in Se-free cells, followed by increased levels of superoxide anions (O2-) and nitric oxide (NO) generation, lipid peroxidation and DNA damage as well. On the other hand, increased enzymatic activity and a significant attenuation of Hg toxicity were measured in Se-treated cells exposed to Hg in all cases. The results of the present study showed that inhibition of Se-GPx activity by Hg could promote a shift in the balance between oxidants and antioxidants in favor of oxidants, resulted in the enhancement of Hg-induced oxidative and genotoxic effects. In addition, Se bioavailability within phagocytic cells, such as haemocytes, could regulate the antioxidant role of Se-GPx, thus reinforcing haemocytes’ immune system against toxic effects induced by pro-oxidants, such as Hg.
Journal: Toxicology in Vitro - Volume 24, Issue 5, August 2010, Pages 1363–1372