重金属镉胁迫对大弹涂鱼肝脏黄嘌呤氧化酶活性的影响

研究了在重金属镉胁迫条件下,大弹涂鱼(Boleophthalmuspectinirostris)肝脏黄嘌呤氧化酶活性的变化。重金属镉胁迫12h时0·5mg/LCd2 组XOD酶活性和对照组比较显著升高(P<0·05);胁迫24h时,大弹涂鱼0·05mg/LCd2 组肝脏的XOD酶活性和对照组比较极显著升高(P<0·01),而0·5mg/LCd2 组酶活性结果却降低;恢复3d时0·5mg/LCd2 又极显著升高(P<0·01)。在镉胁迫解除5d时,3个浓度组的酶活性均极显著降低(P<0·01),其中0·05mg/LCd2 组和0·5mg/LCd2 组的酶活性和对照组酶活性比较无显著差异(P>0·05),5mg/LCd2 组的酶活性极显著低于对照组的酶活性(P<0·01)。实验结果表明,大弹涂鱼肝脏黄嘌呤氧化酶活性对水体中镉污染敏感,有可能用做海洋环境污染的生物标记。

Cadmium-induced changes to the activity of xanthine oxidase in liver of Boleophthalmus pectinirostris

The potential utility of xanthine oxidase (XOD) in liver as indicators of the toxic effects of cadmium chloride on marine fish Boleophthalmus pectinirostris was evaluated. Three concentration groups (0.05 mg/L, 0.5 mg/L and 5 mg/L Cd~ 2 ) and a control group were set up, with each group having two repeats. The XOD activity of Boleophthalmus pectinirostris significantly increased in group 0.5 mg/L Cd~ 2 after 12 h exposure (P<0.05)and in 0.05 mg/L Cd~ 2 group after 24 h exposure(P<0.01), compared with the control. The XOD activity of Boleophthalmus pectinirostris in group 0.5 mg/L Cd~ 2 decreased after 24 h exposure, but significantly increased (P<0.01)after 3 d recovery. (P<0.01).When the three concentration groups were released from exposure for 5 days, all the XOD activity values dropped remarkably(P<0.01), among which, the XOD activity in 0.05 mg/L Cd~ 2 and 0.5 mg/L Cd~ 2 groups settled on the same level as that of the control, while enzyme activity in 5mg/LCd~ 2 group decreased so far as to be significantly lower than the control(P<0.01). Maybe the 5 mg/L Cd~ 2 injured the liver so much as that the interstice of cell membrane became larger than before, resulting in too much loss of XOD. The results indicated that the markers of xanthine oxidase in liver in marine fish Boleophthalmus pectinirostris could denote the cadmium pollution sensitively in seawater and become a valuable biomarker in water pollution examination.