运输胁迫下日本黄姑鱼肝脏抗氧化系统的响应

Responses of antioxidant system to transport stress in the liver of Nibea japonica

研究了运输胁迫对日本黄姑鱼(Nibea japonica)肝脏抗氧化能力的影响。胁迫处理后,鱼体肝脏中抗氧化防御指标受到不同程度的影响。超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力快速升高并显著高于处理前水平(P<0.05),之后逐渐下降到与处理前无显著性差异。谷胱甘肽转移酶(GST)活力在处理后也有所升高,但一直与处理前无显著性差异(P>0.05)。肝脏中维生素C(VC)含量在处理后1 h显著性升高,以应对氧化压力;而自由基含量先升在胁迫0.5 h后快速降低并恢复到处理前水平。丙二醛(MDA)含量在处理后0.5 h达到最高值,然后快速恢复并与处理前无显著性差异(P>0.05)。研究表明,运输胁迫能通过氧化应激反应对日本黄姑鱼造成影响,在胁迫应激反应中SOD和CAT可以作为有效的生物指示剂用于胁迫状态的检测;同时,日本黄姑鱼具有较强的抗氧化防御体系,能较快地清除体内自由基并调整鱼体以适应外界环境的影响。

Physiological parameters in the liver of Nibea japonica were studied to evaluate the responses of antioxidant system to transport stress.After being subjected to transport stress,the activities of antioxidant enzymes were influenced in different degrees.SOD and CAT showed similar changes,their activities increased significantly after exposure to stressor and then dropped to the levels before stress （P ＜ 0.05）.GST activities showed an insignificant increase after stress （P ＞ 0.05）.The concentrations of Vc in the liver also increased significantly 1 h after stress treatment to deal with oxidative stress.Hydroxyl free radical concentrations increased rapidly at 0.5 h after stress and then recovered to the levels before treatment.MDA concentrations peaked at 0.5 h after stress and then decreased to the level that was not significantly different from that before treatment （P ＞ 0.05）.The present study indicated that transport stress could damage N.japonica by oxidant stress,and the enzymes of SOD and CAT could be used as biomarkers in the monitoring of stress status.In addition,an antioxidant defense system that can eliminate free radical rapidly and effectively to adapt fish body to environmental stressors was inferred in this species.