饲料中添加谷胱甘肽对黄颡鱼幼鱼组织谷胱甘肽含量、免疫及抗氧化性能的影响

研究旨在探讨饲料中添加还原型谷胱甘肽(Glutathione, GSH)对黄颡鱼幼鱼(Pelteobagrus fulvidraco)组织谷胱甘肽含量、免疫及抗氧化性能的影响。选用初始体重为(1.32±0.01) g的黄颡鱼800尾, 随机分为5组, 每组4个重复, 每个重复40 尾鱼, 分别投喂基础饲料和添加100、300、500和700 mg/kg GSH的试验饲料, 饲养56d后采样分析, 并采用氯化铵进行96h氨氮应激试验。结果表明: 除100 mg/kg组外, 饲料中添加GSH显著提高黄颡鱼肝脏、血清GSH含量(P<0.05), 当GSH添加量≥300 mg/kg时, 肝脏和血清GSH含量均呈现稳定状态。随着饲料中谷胱甘肽水平的增加, 血清免疫和肝脏抗氧化指标均呈现先升高后降低的趋势, 其中300和500 mg/kg组溶菌酶与碱性磷酸酶活性、300 mg/kg组免疫球蛋白M与补体4含量、500 mg/kg组酸性磷酸酶活性与对照组相比显著升高(P<0.05)。与对照组和700 mg/kg组相比, 300 mg/kg组肝脏超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化酶活性和总抗氧化能力与血清超氧化物歧化酶、谷胱甘肽过氧化酶活性均显著高升高(P<0.05); 且300 mg/kg组血清丙二醛含量显著降低(P<0.05)。氨氮应激96h时, 与对照组相比, 300 mg/kg组肝脏和血清超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化酶活性力均显著升高(P<0.05), 且300 mg/kg组血清丙二醛含量显著降低(P<0.05)。由此可见, 饲料中添加谷胱甘肽能提高黄颡鱼幼鱼组织谷胱甘肽含量、免疫及抗氧化性能, 其中以300—500 mg/kg为宜。

EFFECTS OF DIETARY SUPPLEMENTATION WITH GLUTATHIONE ON TISSUE GSH LEVEL,IMMUNITY, AND ANTIOXIDANT CAPACITY OF JUVENILE YELLOW CATFISH (PELTEOBAGURS FULVIDRACO)

To assess the effects of dietary supplementation with glutathione (GSH) on tissue GSH levels, immunity, and antioxidant capacity of juvenile yellow catfish (Pelteobagrus fulvidraco), a total of 800 yellow catfish with a mean body weight of (1.32±0.01) g were considered and randomly divided into 5 groups with 4 replicates per each group and 40 fish per each replicate as well. During 56d, the fish were fed by a basal diet and four test diets, which supplemented with 100, 300, 500, and 700 mg/kg of reduced GSH, respectively. The results indicated that, except for 100 mg/kg group, supplementation with GSH significantly increased the GSH content in liver and serum of yellow catfish (P<0.05). When GSH level was 300 mg/kg or higher, GSH content in liver and serum was in a stable state. With the increase of glutathione level, the immunity and antioxidant indices were initially increased, and then decreased. The lysozyme and alkaline phosphatase activities in 300 and 500 mg/kg groups, immunoglobulin M (IgM) and complement component 4 (C4) contents in 300 mg/kg group, and acid phosphatase activity in 500 mg/kg group markedly increased, compared with the control group (P<0.05). There were no significant differences (P>0.05) in complement component 3 (C3) and nitric oxide contents among all groups. Compared with the control and 700 mg/kg groups, the liver superoxide dismutase, catalase and glutathione peroxidase activities, total antioxidant capacity and the serum superoxide dismutase, as well as glutathione peroxidase activities in 300 mg/kg group were significantly higher (P<0.05), while the serum malondialdehyde content in that group was considerably lower (P<0.05). Under ammonia-nitrogen stress for 96h, compared with the control group, the liver and serum superoxide dismutase, catalase, and glutathione peroxidase activities in 300 mg/kg group were significantly greater (P<0.05), however, the serum malondialdehyde content in the mentioned group was significantly lower (P<0.05). In conclusion, dietary supplementation with GSH could enhance the tissue GSH level, immunity and antioxidant capacity of juvenile yellow catfish, and the effective range of this enhancement was 300 to 500 mg/kg as well.