[State of the system of antioxidant defense in tissues of the black sea turbot during the spawning].

The system of antioxidant (AO) defense and processes of lipid peroxidation (LP) of the Black Sea turbot Psetta (Scophtalmus) maxima maeotica (L., 1758) have been investigated during the spawning season. The activity of glutathione peroxidase (GP), glutathione reductase (GR), catalase and content of reduced glutathione (GSH) and TBA-reactive products have been determined in gonads, gills, liver, red and white muscles of males and females at different stages of gonad's maturity (V and VI stages). The peculiarities of AO complex and LP depended on tissue specificity and sexual distinctions of the turbot have been found. The turbot females at VI stage were found to have the most significant changes. In gonads and liver the level of TBA-reactive products decreased. In gonads the activities of GP and GR decreased, but the level of GSH increased. In gills of these females the activity of GP and the level of GSH increased, while in the red muscles the activity of catalase raised. In white muscles the activity of GR dropped. In the males' tissues of the turbot at VI stage the growth of the activity of GP in gills and GSH content in white muscles have been found. In all tissues of males the decrease of the TBA-reactive products content has been observed.