Temperature acclimation alters oxidative capacities and composition of membrane lipids without influencing activities of enzymatic antioxidants or susceptibility to lipid peroxidation in fish muscle
Temperature acclimation alters oxidative capacities and composition of membrane lipids without influencing activities of enzymatic antioxidants or susceptibility to lipid peroxidation in fish muscle
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DOI：
10.1242/jeb.036939
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发表时间：
2010-02-01
影响因子：
2.8
通讯作者：
Crockett, E. L.
中科院分区：
文献类型：
--
作者：
Grim, J. M.;Miles, D. R. B.;Crockett, E. L.
外温动物的冷驯化通常会导致氧化能力增强和脂质重塑，这些变化会增加脂质过氧化（LPO）的风险。目前尚不清楚抗氧化酶的活性是否可以缓解LPO增加的可能性。目前的研究解决了这些问题，使用鳉鱼（底heteroclitus macrolepidotus）和蓝鳃金龟（Lepomis macrochirus）适应5和25摄氏度分别为9天和2个月。由于亲和抗氧化剂代谢的温度驯化的影响可能会混淆温度组之间的可变活动水平，一个物种（？冷适应后，鳉鱼的糖酵解（骨骼）肌肉的氧化能力（由细胞色素c氧化酶的活性表明）提高了1.5倍，但心肌的氧化能力没有变化，并且也不受两种组织运动适应的影响。柠檬酸合酶活性没有变化，检测到在任何组织温度驯化后。酶的抗氧化剂（过氧化氢酶和超氧化物歧化酶）的任一肌肉类型的温度或运动驯化不变。从糖酵解肌肉的冷驯化的鳉鱼线粒体富含高氧化性多不饱和脂肪酸（PUFA），包括二酰基磷脂（总碳：总双键）40：8和44：12。然而，当用C11-BODIPY测量时，增加的氧化能力，加上来自冷适应动物的线粒体中PUFA含量升高并不影响LPO易感性。温度适应后氧化能力和酶抗氧化剂之间的明显不匹配将在未来的研究中得到解决。
Cold acclimation of ectotherms results typically in enhanced oxidative capacities and lipid remodeling, changes that should increase the risk of lipid peroxidation (LPO). It is unclear whether activities of antioxidant enzymes may respond in a manner to mitigate the increased potential for LPO. The current study addresses these questions using killifish (Fundulus heteroclitus macrolepidotus) and bluegill (Lepomis macrochirus) acclimated to 5 and 25 degrees C for 9 days and 2 months, respectively. Because the effects of temperature acclimation on pro- and antioxidant metabolism may be confounded by variable activity levels among temperature groups, one species (killifish) was also subjected to a 9-day exercise acclimation. Oxidative capacity of glycolytic (skeletal) muscle (indicated by the activity of cytochrome c oxidase) was elevated by 1.5-fold in killifish, following cold acclimation, but was unchanged in cardiac muscle and also unaffected by exercise acclimation in either tissue. No changes in citrate synthase activity were detected in either tissue following temperature acclimation. Enzymatic antioxidants (catalase and superoxide dismutase) of either muscle type were unaltered by temperature or exercise acclimation. Mitochondria from glycolytic muscle of cold-acclimated killifish were enriched in highly oxidizable polyunsatured fatty acids (PUFA), including diacyl phospholipids (total carbons:total double bonds) 40:8 and 44:12. Increased oxidative capacity, coupled with elevated PUFA content in mitochondria from cold-acclimated animals did not, however, impact LPO susceptibility when measured with C11-BODIPY. The apparent mismatch between oxidative capacity and enzymatic antioxidants following temperature acclimation will be addressed in future studies.