Effect of Salt Stress on ALT and AST Enzymes Activity and Cortisol Level in Adults of Carassius auratus

Abstract

The gradual increment of salinity from 0.1g/l (control) to 4, 8 and 12g/l dealt with stress in adult goldfish Carassius auratus through determination of ALT and AST enzymes activity and cortisol concentration in blood plasma. ALT activity was increased to 56.42, 65.16 and 76.47 IU/l in 4, 8 and 12 g/l salt concentrations respectively, compared with tap water 0.1g/l (control) (48.64 IU/l). AST enzyme activity was also increased to 76.43, 97.58 and 114.48 IU/l in 4, 8 and 12g/l salt concentrations respectively, in comparison with control (54.08 IU/l). Cortisol concentrations in goldfish blood plasma were increased to 0.92, 1.84 and 2.86g/100ml when the salinity raised to 4, 8 and 12g/l, respectively, compared with control (0.73g/100ml). Fish were fed a test diet (31.30% crude protein) during the experiment.