McMurchie E J, Abeywardena M Y, Charnock J S, Gibson R A
Biochim Biophys Acta. 1983 Oct 4;760(1):13-24. doi: 10.1016/0304-4165(83)90119-8.
Diets supplemented with high levels of saturated fatty acids derived from sheep kidney (perirenal) fat or unsaturated fatty acids derived from sunflower seed oil were fed to rats and the effect on heart mitochondrial lipid composition and membrane-associated enzyme behaviour was determined. The dietary lipid treatments did not change the overall level of membrane lipid unsaturation but did alter the proportion of various unsaturated fatty acids. This led to a change in the omega 6/omega 3 unsaturated fatty acid ratio, which was highest in the sunflower seed oil fed rats. Arrhenius plots of the mitochondrial membrane associated enzymes succinate-cytochrome c reductase and oligomycin-sensitive adenosinetriphosphatase (ATPase) after dietary lipid treatment revealed different responses in their critical temperature. For succinate-cytochrome c reductase, the critical temperature was 29 degrees C for rats fed the sheep kidney fat diet and 20 degrees C for rats fed the sunflower seed oil diet. In contrast, no shift in the critical temperature for the mitochondrial ATPase was apparent as a result of the differing dietary lipid treatments. The results suggest that the discontinuity in the Arrhenius plot of succinate-cytochrome c reductase is induced by some change in the physical properties of the membrane lipids. In contrast, mitochondrial ATPase appears insensitive, in terms of its thermal behaviour, to changes occurring in the composition of the membrane lipids. However, the specific activity of the mitochondrial ATPase was affected by the dietary lipid treatment being highest for the rats fed the sheep kidney fat diet. No dietary lipid effect was observed for the specific activity of succinate-cytochrome c reductase. This differential response of the two mitochondrial membrane enzymes to dietary-induced changes in membrane lipid composition may affect mitochondrial oxidative phosphorylation.
给大鼠喂食添加了高水平源自羊肾（肾周）脂肪的饱和脂肪酸或源自葵花籽油的不饱和脂肪酸的饮食，然后测定其对心脏线粒体脂质组成和膜相关酶行为的影响。饮食脂质处理并未改变膜脂质不饱和的总体水平，但确实改变了各种不饱和脂肪酸的比例。这导致ω-6/ω-3不饱和脂肪酸比例发生变化，在喂食葵花籽油的大鼠中该比例最高。饮食脂质处理后，线粒体膜相关酶琥珀酸-细胞色素c还原酶和寡霉素敏感的腺苷三磷酸酶（ATP酶）的阿累尼乌斯曲线显示它们的临界温度有不同反应。对于琥珀酸-细胞色素c还原酶，喂食羊肾脂肪饮食的大鼠的临界温度为29℃，喂食葵花籽油饮食的大鼠的临界温度为20℃。相比之下，不同的饮食脂质处理并未使线粒体ATP酶的临界温度明显偏移。结果表明，琥珀酸-细胞色素c还原酶的阿累尼乌斯曲线中的不连续性是由膜脂质物理性质的某些变化引起的。相比之下，线粒体ATP酶就其热行为而言，似乎对膜脂质组成的变化不敏感。然而，线粒体ATP酶的比活性受饮食脂质处理的影响，喂食羊肾脂肪饮食的大鼠的比活性最高。未观察到饮食脂质对琥珀酸-细胞色素c还原酶比活性的影响。这两种线粒体膜酶对饮食诱导的膜脂质组成变化的不同反应可能会影响线粒体氧化磷酸化。
