Oxidized lipids intake: effect on antioxidative enzimatic activity in rainbow trout Oncorhynchus mykiss (Walbaum)

Objective. To determine the effect, of different oxidation level of lipid, ingested for a period of 20 and 90 days on Catalase (CAT), Superoxide dismutase (SOD) and Glutathione peroxidase (GPx) activities in hepatical and gastrointestinal tissues. Materials and methods. Peroxide Value (PV) and Anisidine Value (AV) were used to detect products of lipidic oxidation in feeds. Data were analyzed using an split plot design and analysis of variance (ANOVA). Means were compared with Tukey test (5%). Results. All rations offered showed high peroxides and secondary products of oxidation levels during all assay and in most cases there were significant differences of oxidative quality between dietary treatments (p?0.05). SOD activity showed decreasing levels in liver for both exposure periods, however, in GIT was generated a significant increase in SOD activity (175%) across time in the individuals subjected to all treatments. CAT activity showed high correlation level with SOD activity for the two periods of exposure and in both organs. Conclusions. GPx activity showed differences for both exposition periods in liver and at 90 day in GIT, indicating high sensitivity of the enzyme to peroxides intake. In all cases were high correlation coefficients (>0.95), suggesting that GIT-GPx activity is a good indicator of the lipid oxidative status of rations.