突降盐度胁迫对大黄鱼(Pseudosciaena crocea)血清生理生化及鳃丝Na+/K+-ATP 酶活性的影响

采用海水盐度由25突降至21、17和13胁迫大黄鱼(Pseudosciaena crocea)的方法,研究了48h内血清生理生化和鳃丝Na+/K+-ATP酶活性的变化。结果表明,实验过程中三个盐度突降组的血清Na+、Ca2+离子浓度均未发生显著变化(P>0.05),血清K+浓度均显著升高(P<0.05),且升高幅度与盐度突降幅度呈正相关,最大值达14.03mmol/L(盐度13组,48h);血清Cl浓度在盐度21组未发生显著变化(P>0.05),17和13组则在48h时显著降低(P<0.05);三个盐度突降组的血清酶ALT、AST、LDH、CK-MB活性均显著高于对照组(P<0.05),随胁迫时间的延长呈先升后降的趋势,且变化幅度均与盐度突降幅度呈正相关;三个盐度突降组的鳃丝Na+/K+-ATP酶活力均呈先升后降的变化趋势,除盐度21组在12h时高于对照组外,活力均显著低于对照组(P<0.05),且降低幅度与盐度突降幅度呈正相关;到实验15天时,死亡率随盐度突降幅度增大而升高。

EFFECTS OF ABRUPT SALINITY DECREASE ON SERUM PHYSIOLOGY, BIOCHEMISTRY AND GILL Na+/K+-ATPase ACTIVITY OF THE LARGE YELLOW CROAKER PSEUDOSCIAENA CROCEA

The effects of abrupt salinity decrease at varying degrees (from 25 to 21, 17 and 13) on serum physiology, biochemistry and gill Na⁺/K⁺-ATPase activity in large yellow croaker Pseudosciaena croceaduring 48h were studied. The results showed that serum Na⁺ and Ca²⁺ had no significant changes (P>0.05) during the whole experiments, the serum K⁺ increased significantly (P<0.05) and the increasing amplitude was positive correlated to salinity decreased degree (the maximum was 14.03mmol/L in 13 group at 48h), and the serum Cl^- decreased significantly (P<0.05) at 48h in 17 and 13 groups. In all the three abrupt salinity decreased groups, the enzyme activities of ALT, AST, LDH and CK-MB increased at first and then decreased, they were all significantly higher (P<0.05) than the control group and the increasing amplitudes were positive correlated to salinity decreased degree. The gill Na⁺/K⁺-ATPase activities increased at first and then decreased in all the three abrupt salinity decreased groups, they were all significantly lower (P<0.05) than the control group (the exception was in 21 group at 12h) and the decreasing amplitudes were positive correlated to salinity decreased degree. The mortalities at 15d showed a positive correlation to the salinity decreased degree.