Joy Susan, Alikunju Aneesa Painadath, Jose Jisha, Sudha Hari Sankar Haridasanpillai, Parambath Prabhakaran Meethal, Puthiyedathu Sajeevan Thavarool, Philip Babu
Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Cochin - 16, India.
Kerala University of Fisheries and Ocean Studies, Panagad, Cochin - 06, India.
J Therm Biol. 2017 Dec;70(Pt B):20-26. doi: 10.1016/j.jtherbio.2017.10.010. Epub 2017 Oct 25.
Fishes are always exposed to various environmental stresses and the chances of succumbing to such stresses are of great physiological concern. Any change in temperature from the ambient condition can induce various metabolic and physiological changes in the body. The present study evaluates the effects of temperature induced stress on the antioxidant profile of Etroplus suratensis such as superoxide dismutase, catalase, glutathione peroxidase and lipid peroxidation. Fishes of same size were kept in a thermostatized bath at three different temperature regimes viz 16°C, 27°C (ambient temperature) and 38°C for 72h. These temperatures were selected based on the CT Max (Critical Thermal Maximum) and CT Min (Critical Thermal Minimum) exhibited by E. suratensis. Superoxide dismutase and catalase activity was found maximum in brain and muscle respectively during the 48th hour of exposure in fishes kept at 38°C. At 16°C the antioxidant response of glutathione peroxidase was maximum in muscles, whereas the lipid peroxidation rate was found to be high in gills compared to other tissues. The profound increase in the levels of oxidative stress related biomarkers indicate that the thermal stressors severely affected oxidative state of E. suratensis by the second day of experiment. Such down-regulation of redox state accompanied with the induction of oxidative stress cascade may lead to physiological damage in various tissues in fishes, in vivo. However current data indicate that a transition to low and high temperature environment from ambient condition severely affected the levels and profile of the antioxidant markers overtime in E. suratensis.
鱼类总是面临各种环境压力，而因这些压力而死亡的可能性在生理上备受关注。与环境条件相比，任何温度变化都可能在鱼体内引发各种代谢和生理变化。本研究评估了温度诱导应激对苏拉特丽鱼抗氧化特征的影响，如超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和脂质过氧化。将相同大小的鱼置于恒温浴中，在三种不同温度条件下，即16°C、27°C（环境温度）和38°C，持续72小时。这些温度是根据苏拉特丽鱼表现出的热上限（CT Max，临界热最大值）和热下限（CT Min，临界热最小值）选定的。在38°C饲养的鱼暴露48小时后，超氧化物歧化酶和过氧化氢酶活性分别在脑和肌肉中达到最高。在16°C时，肌肉中谷胱甘肽过氧化物酶的抗氧化反应最大，而与其他组织相比，鳃中的脂质过氧化率较高。氧化应激相关生物标志物水平的显著增加表明，在实验第二天，热应激源严重影响了苏拉特丽鱼的氧化状态。这种氧化还原状态的下调伴随着氧化应激级联反应的诱导，可能会在体内导致鱼体各种组织的生理损伤。然而，目前的数据表明，从环境条件过渡到低温和高温环境会随着时间的推移严重影响苏拉特丽鱼抗氧化标志物的水平和特征。
