Oxidative stress and band 3 protein function in Liza aurata and Salmo irideus erythrocytes: effect of different aquatic conditions

The aim of this study was to assess the effect of the different aquatic conditions on anion transport of fish erythrocytes through the measurement of the sulphate uptake operating from band 3, the determination of reduced glutathione (GSH) and oxidized glutathione (GSSG). To this purpose, blood samples of 30 Liza aurata and 30 Salmo irideus fishes were collected via caudal vein and washed with physiological buffer. Successively, erythrocytes suspended at 3% haematocrit were used to measure the SO(4) (=) influx by atomic absorption spectrophotometry at 425 nm wavelength and the GSH concentration using an immunodiagnostic assay intended for the quantitative determination of glutathione in ethylenediaminetetraacetic acid in blood. All results were analyzed using unpaired Student's t-test and a P < 0.05 was considered statistically significant. The results of this study showed statistically significant differences about the sulphate uptake and the glutathione levels in S. irideus with respect to L. aurata (P < 0.0001). In conclusion, the different aquatic conditions play an important role on anion transport in fish erythrocytes, showing that environmental differences induce perturbations in erythrocyte membrane and should be evaluated to prevent physiological damages in fishes.