title: Seasonality and toxins effects on oxidative/nitrosative metabolism in digestive glands of the bivalve Mytilus edulis platensis.
abstract: The hypothesis presented here is that oxidative and/or nitrosative metabolism in the bivalve Mytilus edulis platensis is altered by the presence of planktonic toxins. Digestive glands (DG) were isolated from specimens collected in the Argentinean Sea during summer, winter and spring (in the presence of harmful planktonic toxins). The labile iron pool content was not significantly different in DG from animals collected in summer and winter, but was 2.3-fold increased in samples from spring compared to summer collected mollusks. The 2',7' dichlorofluorescein diacetate (DCFH-DA) oxidation, ascorbyl radical/ascorbate and lipid radical/α-tocopherol content ratios showed no significant differences between samples collected in winter and summer. However, spring collected samples showed significantly higher DCFH-DA oxidation rate and oxidative ratios in comparison to DG from mollusks collected in summer. Superoxide dismutase activity decreased by 75% in winter, and 93% in spring, compared to samples collected in summer. Glutathione S-transferase activity decreased by 89% in winter, and 30% in spring, compared to samples collected in summer. Catalase activity in winter animals increased by 3.8-fold in comparison to summer values, with no differences between spring and summer collected mollusks. Nitrite plus nitrate content was not significantly different among samples collected in the three seasons, but nitric oxide content was 8.5- and 2.7-fold higher in samples from winter and spring collected mollusks than values obtained in summer, respectively. These results showed the lack of effects of climatic changes on the integrative oxidative indexes; however, under exposure to toxins, both oxidative and nitrosative metabolisms were affected.
authors.affiliation: Instituto de Bioquímica y Medicina Molecular (IBIMOL)-Universidad de Buenos Aires (UBA), CONICET, Fisicoquímica, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD, Buenos Aires, Argentina.
authors.forename: Paula Mariela
authors.initials: PM
authors.lastname: González
authors.affiliation: Instituto de Bioquímica y Medicina Molecular (IBIMOL)-Universidad de Buenos Aires (UBA), CONICET, Fisicoquímica, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD, Buenos Aires, Argentina. Electronic address: susanap@ffyb.uba.ar.
authors.forename: Susana
authors.initials: S
authors.lastname: Puntarulo
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D003683:Dehydroascorbic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D005452:Fluoresceins / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008387:Marine Toxins / Q000633:toxicity; D049880:Mytilus edulis / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D012621:Seasons; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D005452:Fluoresceins; D008387:Marine Toxins; D017392:Thiobarbituric Acid Reactive Substances; C029569:diacetyldichlorofluorescein; D009569:Nitric Oxide; C000820:semidehydroascorbic acid; D007501:Iron; D002374:Catalase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D003683:Dehydroascorbic Acid
keywords: Bivalve; Digestive gland; Harmful planktonic toxins; Oxidative and nitrosative metabolisms