低温对黑线仓鼠能量代谢、抗氧化能力和氧化应激的影响

Effects of cold temperatures on energy metabolism,antioxidants and oxidative stress in striped hamsters

为探讨低温对机体能量代谢、器官/组织抗氧化能力和过氧化自由基水平的影响及其内在联系,本研究测定了不同时间低温和梯度低温处理的黑线仓鼠的摄食量、体重、主要内脏器官/组织的过氧化物歧化酶(SOD)、过氧化氢酶(CAT)、H2O2和丙二醛(MDA)水平。低温使摄食量显著增加,但未影响体重。低温暴露42 d使心脏和骨骼肌MDA水平、骨骼肌SOD活性显著升高;梯度低温使脑和肾脏H2O2水平、肝脏和骨骼肌SOD活性显著降低,使脑、肝脏、肺、肾脏MDA水平,脑和小肠SOD活性显著升高。抗氧化能力和过氧化自由基水平在不同器官之间相关性存在差异,同一器官内二者的相关性在肾脏为100%,肝脏66.7%,骨骼肌50.0%。结果表明:(1)过氧化自由基的产生与低温暴露的时间和程度有关;(2)不同器官/组织过氧化自由基水平不同;(3)部分器官/组织抗氧化酶活性的变化与过氧化自由基水平的变化密切相关,可能是防止过氧化损伤的主要防御系统。

The present study examined the effects of cold exposure on energy metabolism of striped hamsters,antioxidant activity and super-oxidative damage to organs or tissues,as well as the inter-relationships among the different organs and tissues. Body mass,food intake,superoxide dismutase（SOD） and catalase（CAT） activity,and H2O2 and malonadialdehyde（MDA） levels were measured in striped hamsters exposed to cold temperatures. Cold exposure increased food intake,but had no effect on body mass. MDA levels in heart and muscle,and SOD activity in skeletal muscle,were significantly increased in the hamsters exposed to cold for 42 days relative to those in their counterparts maintained at room temperature. The decreases in ambient temperature significantly decreased H2O2 levels of brain and kidneys,and SOD activity of liver and skeletal muscle,whereas increased MDA levels of brain,liver,lung and kidney,and SOD activity in brain and small intestine. The correlations of antioxidant and super-oxidative radicals differed significantly among the different organs and tissues： the correlations within the same tissues were 100% in kidney,66. 7% in liver and 50. 0% in muscle. These findings suggest that：（1） super-oxidative radical production is associated with the duration and gradient of cold exposure;（2） super-oxidative radical levels differ significantly among the different organs and tissues;（3） antioxidant activity is significantly correlated with super-oxidative radicals levels in some organs and tissues,which may be an important defensive system against the oxidative damages.