镉对罗非鱼脑AChE及组织中代谢酶的影响

Effects of Cd on brain AChE and metabolic enzymes in tissues of T. Nilotics.

将尼罗罗非鱼分别在含0.5mg/LCd和5.0mg/LCd的水环境中染毒28d,对其脑乙酰胆碱脂酶(AChE)及鳃、肝脏和心脏中的乳酸脱氢酶(LDH)、丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)分别进行测定.结果表明,高浓度或长期的低浓度镉污染可抑制脑AChE的活性.高镉组中LDH在三个组织中都极显著下降,下降的程度依次为:肝脏>心脏>鳃,而在低镉组中LDH在后期显著升高;肝、心及鳃中ALT和AST在两组中匀显著下降,其中ALT下降程度依次为肝>心>鳃;AST依次为心>肝>鳃.可见,高浓度镉可引起鱼的神经机能紊乱和能量代谢障碍;使鱼的组织细胞受到不同程度的损害,其中对肝脏细胞的损害最为严重,其次是心脏和鳃.

T. Nilotics was exposed to two water environments which contained 0.5 mg/L Cd and 5.0 mg/L Cd, respectively, for about 28 days . The brain acetylcholinesterase (AChE) and the lactic dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartic transaminase (AST) in gill, liver and heart were assayed. The result shows that both high dose of Cd and low dose of Cd pollution for a long time led to inhibition of AChE. LDH activity in the three organs significantly decreased in the high dose Cd group,the sequence of degree of decrease being liver>heart>gill. On the other hand, in the low Cd group, the LDH activity significantly rose at the late stage. ALT and AST remarkable decreased in both Cd groups, the levels of ALT activity in organs being 1iver>heart>gill and of AST heart>liver>gill. It is concluded that higher dose of Cd may disturb nervous functions of T. Nilotics and glycometabolism process. In addition, Cd can damage bistiocyte and is more harmful to hepatic cell then to heart and gill cell.