The effect of moderate and acute hypoxia on the antioxidant enzyme complex of the tissues of the black sea mussel <i>Mytilus galloprovincialis</i>

Abstract

The effect of moderate (2 mg O2/L) and acute (1 mg O2/L) hypoxia on the state of the antioxidant complex of the mussel Mytilus galloprovincialis (Lamarck, 1819) was studied. The activity of superoxiddismutase (SOD), catalase and glutathione peroxidase (GP) in the hepatopancreas and gills of the mollusk was determined. The reactions of the AO complex of mussels to oxygen deficiency depended on the degree of hypoxic exposure and had tissue specificity. Acute hypoxia had a more pronounced effect on the mussel than moderate. In the gills of the mollusk under acute hypoxia, an increase in the activity of all the studied enzymes was observed. In the digestive gland of the mussel, under these conditions, only catalase activity increased, and SOD significantly decreased. Under moderate hypoxia conditions, the AO protection of the mollusk gills was provided by SOD and GP, and in hepatopancreas – by activation of catalase and GP. These reactions indicate the development of moderate oxidative stress in mussel tissues under both hypoxia regimes. The features of the AO response of gills and hepatopancreas reflect their tissue-specific sensitivity to the effects of oxygen deficiency.