饲喂甘草后低盐胁迫对尖吻鲈相关酶活性的影响

Asian Seabass Lates calcarifer under Low Salinity Stress

为探究饲喂甘草后低盐胁迫对尖吻鲈相关酶活性的影响,在盐度32.1下,将体质量(13.89±2.50)g的尖吻鲈饲养在500L玻璃纤维桶中,投喂添加0、10、30g/kg和50g/kg甘草粉的饲料饲养56d,之后转入100L盛有自来水的塑料桶中进行24h胁迫试验,对相关酶活性进行检测和分析。试验结果表明:胁迫后,对照组尖吻鲈幼鱼血清过氧化氢酶活性和总抗氧化能力有不同程度升高;胁迫后溶菌酶活性随甘草添加量的增加而升高,而丙二醛含量则相反;与胁迫前相比,胁迫后谷胱甘肽过氧化物酶活性和丙二醛含量显著降低(P<0.05);胁迫后肝脏总超氧化物歧化酶、过氧化物酶活性和总抗氧化能力随甘草添加量的增加逐渐降低(P<0.05);胁迫后各组过氧化物酶活性、丙二醛含量和总抗氧化能力均显著高于胁迫前相应各组,而谷胱甘肽过氧化物酶活性恰好相反;胁迫后除10g/kg添加组差异不显著外,其他各组鳃Na+/K+-ATP酶活性均显著低于胁迫前相应各组(P<0.05)。研究结果表明,饲料中添加甘草可以增强尖吻鲈机体活力以及抗应激和环境胁迫的能力。

In order to explore changes in the antioxidant capacity of Asian seabass Lates calcarifer under low-salt stress after feeding Radix Glycyrrhizae,Asian seabass with body weight of(13.89±2.50)g were reared in a 500 L fiberglass bucket and fed diets containing 0(group 1),10(group 2),30(group 3)and 50 g/kg(group 4)of Radix Glycyrrhizae powder for 56 days at water temperature of 28.5℃and salinity of 32.1.At the end of the culture,Asian seabass with body weight of(28.51±3.47)g was transferred to 100 L of freshwater plastics buckets filled with tap water for 24 hours,and then activities and contents of antioxidant-related enzymes were determined.The results showed that the activities of serum catalase and total antioxidant capacity in group 1(control)were improved in varying degrees during the experiment.At the end of the low salinity stress,the activity of lysozyme was found to be increased with the increase in Radix Glycyrrhizae powder doses,the amount of malondialdehyde to be decreased;comparing to the treatment,and the activity of glutathione peroxidase and the amount of malondialdehyde to be decreased significantly(P<0.05).The activities of liver total superoxide dismutase,and peroxidase and total antioxidant capacity were decreased gradually with the increase in dietary Radix Glycyrrhizae powder content(P<0.05).Furthermore,the activities of peroxidase and total antioxidant capacity and the amount of malondialdehyde in each group after the experiment were significantly higher than ever before,while the activity of glutathione peroxidase was decreased.Except for group 2,the activity of Na^(+)/K^(+)-ATPase in gills in other groups after the experiment were significantly lower than ever before(P<0.05).In conclusion,the dietary Radix Glycyrrhizae powder can enhance the body vitality,anti-stress and anti environmental stress capabilities of juvenile Asian seabass.