Responses of antioxidases in different tissues of Acipenser schrenckii to increased salinity in water

Activities of SOD and CAT in different tissues of Acipenser schrenckii at salinities of 10, 20 and 25 during salinity acclimation were measured. In this study, SOD and CAT activities in liver tissue were the highest among the tissues tested. SOD activity in different tissues declined with the increasing salinity, which is significantly different from that in the control. With the increase of salinity acclimation time, activity of SOD in different tissues gradually increased, except in heart and kidney. CAT activity in different tissues tested at salinity 10 was significantly (P0.05) lower than that in the control. At salinities of 10, 20 and 25, there were no significant difference (P0.05) in CAT activity in heart tissue. But they were all lower than that in the control group. Activity of CAT in liver, spleen and kidney showed the same pattern of change, decreased first and then increased. At salinity of 25, CAT activities in liver and kidney tissues were significantly higher (P0.05) than those in the control group. The study showed that SOD and CAT in different tissues of A.schrenckii were inhibited first by the increasing salinity and then recovered,to some extent,with the elapse of salinity acclimation time, which maybe attributed to the osmoregulation ability of A. schrenckii.