低氧–复氧对脊尾白虾呼吸代谢和抗氧化酶活力的影响

Effects of hypoxia and reoxygenation on respiratory metabolism enzyme and antioxidant enzyme activities in Exopalaemon carinicauda

中文关键词: 脊尾白虾  低氧  呼吸代谢  抗氧化能力

英文关键词: Exopalaemon carinicauda  Hypoxia  Respiratory metabolism  Antioxidant capacity

中文摘要:

      以静室呼吸耗氧–复氧为实验组，持续充气组为对照组。于0、1、2、4、5 h及复氧1、4、8 h检测并分析了水体溶解氧(DO)和脊尾白虾(Exopalaemon carinicauda)组织主要呼吸代谢及抗氧化酶活力。结果显示，随着时间的延长，实验组DO不断降低，且显著低于对照组(P<0.05)。脊尾白虾鳃、肝胰腺和肌肉细胞色素C氧化酶(CCO)、琥珀酸脱氢酶(SDH)活力降低；乳酸脱氢酶(LDH)、延胡索酸还原酶(FRD)活力升高，SDH/FRD值降低。复氧后，3种组织SDH、LDH和FRD活力恢复至对照组，肌肉CCO活力升高，在复氧8 h时低于对照组(P<0.05)；SDH/FRD值升高。随着时间的延长，3种组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPX)和谷胱甘肽S转移酶(GST)活力均先升后降，但肝胰腺的过氧化物酶(POD)活力降低，而在鳃和肌肉中呈波动性变化；复氧后，3种组织SOD、CAT、GPX和GST活力均恢复至对照组水平，但鳃和肌肉的POD在复氧8 h时均低于对照组(P<0.05)。研究表明，随着DO的降低，脊尾白虾有氧代谢逐渐降低，无氧代谢逐渐升高。复氧后，有氧代谢能力又逐渐恢复。上述抗氧化酶可能在脊尾白虾应对低氧-复氧中产生的氧化损伤发挥着重要作用。

英文摘要:

      Here we clarify the effects of gradually changing hypoxia and reoxygenation on respiratory metabolism and antioxidant capacity in Exopalaemon carinicauda. In the present study, we investigated oxygen consumption and reoxygenation in a respiratory chamber in which we first created a low-oxygen environment by preventing aeration and isolating the air, following which the chamber was aerated and reoxygenated. Continuously aerated groups were used as the control groups. Water and shrimp tissue samples were taken after 0, 1, 2, 4, 5 h of hypoxia and 1, 4, 8 h of reoxygenation from the beginning of the experiment. Further, we recorded the dissolved oxygen concentration of the water and the activities of the main respiratory metabolism enzyme and the antioxidant enzyme in shrimp tissues at different time points. The results indicated that over time, the dissolved oxygen concentration in the experimental group significantly decreased and was significantly lower than that in the control group (P<0.05). The dissolved oxygen concentration in the control group remained stable. After reoxygenation, the dissolved oxygen concentration in the experimental group quickly returned to the control level. Over time, cytochrome c oxidase (CCO) and succinate dehydrogenase (SDH) activities in the gill, hepatopancreas, and muscle tissue from the experimental group continuously decreased, lactic dehydrogenase (LDH) and fumaric reductase (FRD) activities continuously increased. In addition, the value of SDH/FRD showed a gradually decreasing trend. During reoxygenation, SDH, LDH, and FRD activities gradually returned to the levels of the control group in three organizations; CCO activity in muscle continuously increased but was significantly lower than that in the control group at 8 h (P<0.05). Furthermore, the value of SDH/FRD also showed a gradually increasing trend. Over time, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione s-transferase (GST) in the gill, hepatopancreas, and muscle tissue showed a trend of first increasing and then decreasing, but the activities of peroxidase (POD) continuously decreased in the hepatopancreas, while fluctuating in both, the gill and the muscle tissue. During reoxygenation, the activities of SOD and CAT in the gill, hepatopancreas, and muscle tissue all showed a trend of first increasing and then decreasing, but showed no significant difference with the control group at 8 h (P>0.05). With the increase of recovery time, the activities of GPX and GST in the three tissues returned to the level of the control group, but the activities of POD in gill and muscle tissue were significantly lower than those in the control group under reoxygenation at 8 h. The results show that with the continuous decrease in dissolved oxygen concentration, the aerobic metabolic level of E. carinicauda gradually decreased, and the anaerobic metabolic capacity gradually increased, while during reoxygenation, the aerobic metabolic capacity gradually recovered. Antioxidant enzymes such as SOD, CAT, POD, GPX, and GST may play an important role in responding to oxidative damage during hypoxia and reoxygenation.