暂养过程中亚硒酸钠对斑点又尾鮰免疫应激的缓解作用

为阐明暂养过程中亚硒酸钠对斑点叉尾鮰血液指标的影响，本研究将斑点叉尾鮰随机分为4组（每组20条，鱼水比130 g:1 L），添加亚硒酸钠（Na2SeO3）至水中初始浓度分别为0（对照组）、0.1、0.2、0.5 mg/L，禁食暂养4 d，每天取样检测鮰鱼肝脏代谢、能量代谢、免疫蛋白及氧化应激等相关血清生化指标。结果表明，暂养初期，0.1 mg/L Na2SeO3组血清中谷丙转氨酶（ALT）和谷草转氨酶（AST）指标值显著（p<0.05）低于0.2 mg/L组和0.5 mg/L组。随着暂养天数增加，Na2SeO3组血清ALT活力和AST活力总体呈下降趋势；其中0.1 mg/L Na2SeO3组暂养2 d时，ALT和AST活力跟对照组相比均显著降低（p<0.05），最大降幅分别达75.39%和170.13%。随暂养时间延长，0.1 mg/L Na2SeO3组MDA浓度大部分显著（p<0.05）低于0.2 mg/L组和0.5 mg/L组；血糖先显著升高（p<0.05）后显著降低（p<0.05），与对照组趋势相反，延缓了血糖下降速率。以上结果表明，鱼水比130 g:1 L时，Na2SeO3在水中初始浓度0.1 mg/L暂养2 d左右，可缓解斑点叉尾鮰的应激反应、延缓禁食导致的血糖降低过程并提高其抗氧化能力。

Alleviating Action of Sodium Selenite on Immunological Stress in Ictalurus punctatus during Temporary Cultivation

To determine the effect of sodium selenite (Na2SeO3) on blood indexes of Ictalurus punctatus during the process of temporary cultivation, in this study, the Ictalurus punctatus were randomly divided into four groups (n=20 with fish water ratio of 130 g: 1 L in each group), the Na2SeO3 was added to the water, and the initial concentrations were 0 (control group), 0.1, 0.2, 0.5 mg/L, respectively. Temporary cultivation for 4 days with fasting, the related serum biochemical indexes such as liver metabolism, energy metabolism, immune protein and oxidative stress were detected every day. The results showed that, at the initial stage of cultivation, the alanine aminotransferase (ALT) and glutamic oxaloacetic transaminase (AST) in serum of 0.1 mg/L Na2SeO3 group were significantly lower than that of 0.2 mg/L group and 0.5 mg/L group (p<0.05). With the increase of cultivation days, ALT and AST activities in serum in the Na2SeO3 groups were decreased. And the activities of ALT and AST in serum of 0.1 mg/L Na2SeO3 group were significantly reduced in the 2 days of temporary cultivation (p<0.05) compared with the control group, amounted to 75.39% and 170.13% respectively. With the prolongation of cultivation time, the concentration of MDA in the 0.1 mg/L Na2SeO3 group was significantly lower than that in the 0.2 mg/L and 0.5m/L groups. Moreover, the blood glucose in the 0.1 mg/L Na2SeO3 group increased significantly (p<0.05) at first and then decreased significantly (p<0.05) with the increase of cultivation time, which was contrary to the trend of the control group, delaying the rate of blood glucose decline. The above results showed that when the fish water ratio was 130 g:1 L, the initial concentration of Na2SeO3 in water was 0.1 mg / L for about 2 days, which could alleviate the stress response, delay the process of blood glucose reduction caused by fasting, and improve the antioxidant capacity of Ictalurus punctatus.