没食子酸暂养对大口黑鲈抗氧化性能及运输后肌肉品质的影响OACHSSCD

[Objective]This study aims to investigate the effects of short-term rearing with gallic acid on the antioxidant status of largemouth bass(Micropterus salmoides)subjected to capture stress and to determine the appropriate rearing concentration,and to evaluate its regulatory role of gallic acid in mitigating stress responses and maintaining basic muscle quality during simulated transport.[Methods]Largemouth bass subjected to capture stress were reared in water containing 0,5,and 20 mg/L gallic acid(GA)for 7 days.The effects of this treatment on the histological structure of the liver,spleen,and kidney,as well as on antioxidant enzyme activities and the expression of antioxidant-and inflammation-related genes were analyzed to screen for the optimal GA concentration.Subsequently,simulated transport trials lasting 0,6,12,and 24 hours were conducted on the fish treated with the optimal GA concentration.Blood stress indicators and changes in basic muscle quality were measured during transport,and the integrated biomarker response(IBR)was employed to comprehensively assess the health status of the fish under transport stress.[Results]Conditioning for 7 days alleviated capture-induced oxidative stress and promoted recovery of the antioxidant status in the liver,spleen,and kidney.Compared with the water-only conditioning group,the 5 mg/L GA treatment showed the best effects,reducing hepatocyte dispersion,swelling,and vacuolization,as well as decreasing macrophage aggregation in the spleen and kidney.After 5 mg/L GA treatment,GSH content and GSH-Px activity significantly increased:in the liver,from 13.57 and 25.36 U/mg to 15.89 and 27.92 U/mg,respectively;in the spleen,from 5.60 and 12.30 U/mg to 5.98 and 13.58 U/mg,respectively;and in the kidney,from 10.49 and 32.31 U/mg to 12.06 and 34.33 U/mg,respectively.The response of the Nrf2/Keap1-related antioxidant pathway was also promoted.Simulated transport results showed that,compared with the water-only conditioning group,5 mg/L GA treatment significantly reduced blood glucose levels during 0-24 h of transport,improved flesh color,and significantly decreased blood cortisol levels during 6-24 h of transport.IBR analysis indicated that the GA-treated group exhibited lower overall stress levels at each transport time point.[Conclusion]Short-term rearing with 5 mg/L GA improves the antioxidant status of the liver,spleen,and kidney of largemouth bass,enhances the overall stress tolerance of the fish,further alleviates early transport stress,and maintains basic muscle quality after transport.These findings provide a theoretical basis for health regulation of largemouth bass prior to transport.