Antioxidant Mechanisms of the NereididLaeonereis acuta(Anelida: Polychaeta) to Cope with Environmental Hydrogen Peroxide

• Published in: Physiological and biochemical zoology 2005-07, Vol.78 (4), p.641-649
• Main Authors: Rosa, Carlos E. da, Iurman, Mariana G., Abreu, Paulo C., Geracitano, Laura A., Monserrat, José M.
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants; Body regions; DNA damage; Enzymes; Hydrogen; M region; Peroxides; Secretion; Worms
• ISSN: 1522-2152; 1537-5293
• DOI: 10.1086/430229

Hydrogen peroxide (H2O2) is a naturally occurring prooxidant molecule, and its effects in the macroinvertebrate infauna were previously observed. The existence of a gradient of antioxidant enzymes activity (catalase [CAT], glutathione peroxidase [GPx], superoxide dismutase [SOD], and glutathione‐S‐transferase [GST]) and/or oxidative damage along the body of the estuarine polychaetaLaeonereis acuta(Polychaeta, Nereididae) was analyzed after exposure to H2O2. Because this species secretes conspicuous amounts of mucus, its capability in degrading H2O2was studied. The results suggest thatL. acutadeal with the generation of oxidative stress with different strategies along the body. In the posterior region, higher CAT and SOD activities ensure the degradation of inductors of lipid peroxidation such as H2O2and superoxide anion (O2 •−). The higher GST activity in anterior region aids to conjugate lipid peroxides products. In the middle region, the lack of high CAT, SOD, or GST activities correlates with the higher lipid hydroperoxide levels found after H2O2exposure. Ten days of exposure to H2O2also induced oxidative stress (lipid peroxidation and DNA damage) in the whole animal paralleled by a lack of CAT induction. The mucus production contributes substantially to H2O2degradation, suggesting that bacteria that grow in this secretion provide this capability.