缢蛏在急性温度胁迫下的氧化应激响应及生理代谢变化

Study on oxidative stress response and physiological metabolism of Sinonovacula constricta under acute temperature stress

摘要:

为探究急性温度胁迫下缢蛏（Sinonovacula constricta）的氧化应激响应及生理代谢变化，评价缢蛏适应气候变化的能力，将暂养净化后的缢蛏分为7组，分别在4、10、15、20（对照）、25、30和35℃的水浴温度下胁迫6 h后，缓慢回复至对照组温度（20℃），检测各组缢蛏鳃及消化腺组织中超氧化物歧化酶（superoxide dismutase，SOD）活性、过氧化物酶（peroxidase，POD）活性、过氧化氢酶（catalase，CAT）活性、总抗氧化能力（total antioxidant capacity，T-AOC）、丙二醛（malondialdehyde，MDA）含量、还原性谷胱甘肽（glutathione，GSH）含量、H₂O₂含量。结果表明：各指标在经过6 h，4、10、30、35℃的胁迫后均发生显著变化；相较低温胁迫，在高温胁迫下的SOD、POD、MDA、GSH等指标都有更显著的变化；在24 h温度回复后，4℃低温组和35℃高温组的各指标均不能恢复到对照组水平。研究表明，低温和高温胁迫均会引起缢蛏鳃和消化腺中抗氧化系统的失衡，导致活性氧的显著变化；SOD、CAT、POD和GSH在机体应对温度胁迫导致的氧化损伤中起到不同的作用；在极端环境温度变化超过缢蛏的耐受极限，达到致死温度时，机体的抗氧化调节系统失衡，会造成不可修复的氧化损伤，影响其正常的生理活动。

Abstract:

To investigate the oxidative stress response and physiological metabolic changes of Sinonovacula constricta under acute temperature stress, and to evaluate the ability of S.constricta to adapt to climate change, S.constricta after holding and purification were divided into 7 groups, which were subjected to temperature stress at 4 ℃, 10 ℃, 15 ℃, 20 ℃ (CK), 25 ℃, 30 ℃, 35 ℃ under water bath. After 6 hours, it slowly returned to the control temperature (20 ℃).The changes of superoxide dismutase activity, peroxidase activity, catalase activity total antioxidant capacity and malondialdehyde content, reduced glutathione content, hydrogen peroxide content of gill and digestive gland of S.constricta were measured in each group. The results showed that the group at 4 ℃, 10 ℃, 30 ℃, 35 ℃ showed significant changes after 6 h of stress; compared with the low temperature stress, SOD, POD, MDA, GSH and other indicators all had more significant changes under the temperature stress of the high temperature; after the temperature was restored at 24 h, the indexes of the low temperature group at 4 ℃ and the high temperature group at 35 ℃ could not be restored to the levels of the control group. Studies have shown that both low temperature and high temperature stresses cause an imbalance of the antioxidant system in the tissue, resulting in a significant change in the active oxygen content; SOD, CAT, POD and GSH play different roles in the body’s response to oxidative damage caused by temperature stress; and when the extreme environmental temperature changes beyond the tolerance limit of the tissue, reaching the lethal temperature, the imbalance of the body’s antioxidant regulation system will cause irreversible oxidative damage and affect its normal physiological activities.