SEASONAL CHANGES IN ANTIOXIDANT DEFENCE SYSTEM ON BROWN TROUT (SALMO SP.) IN MUNZUR STREAM

The aim of the present study was to evaluate the oxidant and antioxidant status of the indigenous brown trout (Salmo sp.) caught from Munzur stream (Tunceli, Turkey) at different seasons in different tissues. Glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), total antioxidant status (TAS) and total oxidant status (TOS) levels were measured. These measurements were read in a microplate reader using commercial kits with ELISA method. At the end of the study, significant variations of oxidative stress biomarkers were observed between seasons and tissues. The results of this study show that oxidative stress responses in tissues of Salmo sp. are sensitive to the tissues and the seasons in relation to the contaminants, climatic parameters and reproductive period in Munzur stream. The selected parameters are in valuable biomarkers for monitoring of water systems since at molecular levels they give an early warning signal of xenobiotics on aquatic organisms. It was concluded that the measurement of antioxidants biomarkers known such as SOD, CAT and GSH-Px activities, TAS and TOS levels may also be promising indicators of an oxidant impact on aquatic organisms.