牛磺酸和谷氨酰胺对石斑鱼的应激缓解作用

Stress Relieving Effect of Taurine and Glutamine on Grouper Hybrid

为缓解珍珠龙胆石斑鱼在低温无水保活过程中的应激作用,将体质量(800±50)g的石斑鱼暂养在添加20 mg/L牛磺酸及0、20、25、30 mg/L谷氨酰胺的水中(对照组未添加牛磺酸和谷氨酰胺),分析新鲜状态,低温无水保活0、6、12 h及复水后石斑鱼血浆生化指标、肝脏代谢物质和抗氧化酶活性及肌肉物质代谢情况。结果表明,暂养水中添加牛磺酸和谷氨酰胺能够显著降低石斑鱼应激激素(皮质醇)的产生,使其更快地适应低温环境。石斑鱼在无水保活过程中肝脏代谢发生紊乱,肝脏过氧化氢酶、总超氧化物歧化酶、谷胱甘肽过氧化物酶活性及总抗氧化能力均增强。随着无水保活时间的延长,谷草转氨酶和谷丙转氨酶活性及葡萄糖、尿素氮、皮质醇含量稳步上升,在保活6 h或12 h时达到峰值。各组石斑鱼在无水保活过程中肌肉糖原含量显著下降,而乳酸含量明显增加,复水后有所恢复。经牛磺酸和谷氨酰胺处理的石斑鱼尤其是牛磺酸+30 mg/L谷氨酰胺组的相关指标变化显著低于对照组和牛磺酸处理组,表明暂养水中添加牛磺酸和谷氨酰胺有助于珍珠龙胆石斑鱼维持无水保活过程中生理生化指标的稳定,可有效减缓其氧化应激损伤程度。

In order to relieve the stress effect of hybrid grouper(Epinephelus fuscoguttatus♀×E.lanceolatus♂)during low-temperature and air exposure alive,the grouper with body weight of(800±50)g were temporarily retained in seawater containing 0(control group)and 20 mg/L taurine(taurine group),and then 0(control group),20,25 and 30 mg/L glutamine.The plasma biochemical indices,liver metabolites,antioxidant enzyme activities and muscle metabolism of the grouper in fresh state,low-temperature and air exposure alive for 0,6,12 h,and after revival were analyzed.The results showed that there was significant decrease in the concentration of cortisol in the grouper exposed to addition of taurine and glutamine in the temporary water,leading to enable to quickly adapt the low temperature environments.The liver metabolism was disturbed during air exposure alive,with enhanced activities of catalase,total superoxide dismutase,and glutathione peroxidase and total antioxidant capacity in liver.The contents of glucose,urea nitrogen and cortisol,and the activities of aspartate aminotransferase and alanine aminotransferase were found to be increased steadily with the prolongation of air exposure,with the peak value at 6 or 12 h.The significant decrease in content of muscle glycogen was observed in each group,and the significant increase in content of lactic acid and gradual recovery after revival.The changes in related indicators of the grouper treated with taurine and glutamine solution,especially taurine and 30 mg/L glutamine group,were shown to be significantly lower than those in control group and taurine treatment group,indicating that the addition of taurine and glutamine into water led to the hybrid grouper to maintain the stability of physiological and biochemical indicators and effectively alleviate the degree of oxidative stress damage during air exposure.