副溶血弧菌对罗氏沼虾肝胰腺和鳃组织中呼吸相关酶活性及抗氧化酶基因表达的影响

【目的】探讨副溶血弧菌（Vibrio parahaemolyticus）对罗氏沼虾（Macrobrachium rosenbergii）肝胰腺和鳃组织中呼吸相关酶活性和抗氧化酶基因的影响，以期为罗氏沼虾免疫机理研究和病害防治提供参考依据。【方法】选取规格整齐、健康的罗氏沼虾，分别注射PBS溶液（对照组）和副溶血弧菌（试验组），在第1、3、6、12、24、48、72和96h统计累计存活率，并取肝胰腺和鳃组织进行呼吸相关酶活性及抗氧化酶相关基因表达测定。【结果】罗氏沼虾感染副溶血弧菌后，随着时间的推移，其累计存活率逐渐下降，在96h累计存活率为72%。感染副溶血弧菌后，其肝胰腺中的ATP合酶、细胞色素C氧化酶和NADH脱氢酶活性随时间延长均呈先降低后上升最后趋于对照组水平的变化趋势，且在6~24h 3种酶活性均显著低于对照组（P<00.05，下同），之后酶活性逐步上升；活性氧（ROS）含量则呈先上升后下降的变化趋势，且在6~48h显著高于对照组；超氧化物歧化酶（SOD）基因、过氧化氢酶（CAT）基因及谷胱甘肽过氧化物酶（GPX）基因相对表达量呈先升高后降低再升高的变化趋势。在鳃组织中，ATP合酶、细胞色素C氧化酶和NADH脱氢酶的活性随着感染时间的延长呈先降低后上升至趋于对照组水平，在6~72h 3种酶活性不同时间段表现出显著下降趋势；ROS含量则呈先上升后下降的变化趋势；SOD、CAT和GPX基因相对表达量呈先升高后降低再升高的变化趋势，且均在感染6h显著上调至最大值，其中GPX基因相对表达量在12~48h显著下调低于对照组，并在72h逐渐上调。【结论】副溶血弧菌感染罗氏沼虾后对肝胰腺和鳃组织中的呼吸相关酶及抗氧化酶基因产生显著影响，ROS水平呈上升趋势。虽然罗氏沼虾能通过自我调节呼吸相关酶和抗氧化酶基因促使机体抵御病原体入侵，但超过机体自我调节的限度时会对机体造成损伤。

Effects of Vibrio parahaemolyticus on activities of respiratoryrelated enzymes and gene expression of antioxidant enzymes in hepatopancreas and gill of Macrobrachium rosenbergii

【Objective】To investigate the effects of Vibrio parahaemolyticus on the activities of respiratory-related enzymes and antioxidant enzyme genes in hepatopancreas and gill of Macrobrachium rosenbergii，in order to provide reference for the immune mechanism research and disease control of M. rosenbergii.【Method】Regular and healthy M. rosenbergii was selected and injected with PBS solution（control group）and V. parahaemolyticus（experimental group）respectively. The cumulative survival rate was counted at the 1，3，6，12，24，48，72 and 96 h，and the activities of respiratory related enzymes and the expression of antioxidant enzyme related genes were measured in hepatopancreas and gill tissues.【Result】After being infected with V. parahaemolyticus，the cumulative survival rate of M. rosenbergii gradually decreased with the passage of time，and the cumulative survival rate was 72% at 96 h. After infection with V. parahaemolyticus，compared with the control group，the activities of ATP synthase，cytochrome C oxidase and NADH dehydrogenase in the hepatopancreas of M. rosenbergii in the experimental group decreased at first and then increased and finally tended to be the level of the control group. At 6 to 24 h，the activities of the three enzymes were significantly lower than those in the control group（P<0.05，the same below），and then gradually increased. The reactive oxygen species（ROS）content increased at first and then decreased，and was significantly higher than that in control group at 6-48 h. Superoxide dismutase （SOD）gene，catalase（CAT）gene and glutathione peroxidase（GPX）gene increased at first，then decreased and then increased. In the gill tissue of M. rosenbergii in the experimental group，the activities of ATP synthase，cytochrome C oxidase and NADH dehydrogenase decreased at first and then increased to the level of the control group，and the activities of the three enzymes decreased significantly at 6-72 h. The activity of reactive oxygen species increased at first and then decreased. The relative expression of SOD gene，CAT gene and GPX gene increased first，then decreased and finally increased，and both of them significantly increased to the maximum at 6 h after infection，in which the relative expression of GPX gene significantly decreased from 12-48 h to lower than that of the control group，and gradually increased at 72 h. 【Conclusion】V. parahaemolyticus infection of M. rosenbergii has significant effect on antioxidant enzyme genes and respiratory-related enzymes in hepatopancreas and gill tissues，the level of ROS increases. Although M. rosenbergii can resist pathogen invasion by self-regulating antioxidant enzyme genes and respiratory-related enzymes，it will cause damage to the body when it exceeds the limit of self-regulation.