Dipartimento delle Scienze Biologiche, Sezione di Fisiologia, Università di Napoli Federico II, Naples, Italy.
J Bioenerg Biomembr. 2011 Aug;43(4):387-97. doi: 10.1007/s10863-011-9371-6. Epub 2011 Jul 6.
In cold exposed rats, it is known that vitamin E induces an increase in the respiration of the whole mitochondrial population isolated from liver. To obtain information on the effects of cold exposure and vitamin E treatment on the dynamics of mitochondrial population, we determined characteristics of rat liver mitochondrial fractions, resolved at 1,000 (M(1)), 3,000 (M(3)), and 10,000 g (M(10)). We found that cold exposure increased the liver content of total mitochondrial proteins irrespective of vitamin E treatment. Conversely, protein distribution among the mitochondrial subpopulations was differentially affected by cold and antioxidant integration. In a cold environment, the M(1) fraction, characterized by the highest O(2) consumption and H(2)O(2) production rates, underwent a remarkable protein content reduction, which was attenuated by vitamin E. These changes were dependent on the opposite effects of the two treatments on mitochondrial oxidative damage and susceptibility to swelling. The proteins of the other fractions, in which the above effects were lower, underwent smaller (M(3)) or no change (M(10)) in the treatment groups. The cold also led to an increase in O(2) consumption of the M(1) fraction which was accentuated by vitamin E treatment. This phenomenon and the vitamin-induced recovery of the M(1) proteins supply an explanation of the previously reported increase in the respiration of the whole mitochondrial population induced by vitamin E in the liver from cold exposed rats.
在寒冷暴露的大鼠中，已知维生素 E 可诱导从肝脏分离的整个线粒体群体的呼吸增加。为了获得有关冷暴露和维生素 E 处理对线粒体群体动力学的影响的信息，我们确定了在 1000（M(1)）、3000（M(3)）和 10,000 g（M(10)）下分离的大鼠肝线粒体分数的特征。我们发现，冷暴露增加了总线粒体蛋白的肝含量，而与维生素 E 处理无关。相反，冷和抗氧化剂整合对线粒体亚群的蛋白质分布有不同的影响。在寒冷环境中，M(1)部分以最高的 O(2)消耗率和 H(2)O(2)产生率为特征，其蛋白质含量显著减少，而维生素 E 可减轻这种减少。这些变化取决于两种处理对线粒体氧化损伤和肿胀易感性的相反作用。其他部分的蛋白质，其上述作用较低，在处理组中经历较小的（M(3））或没有变化（M(10））。寒冷还导致 M(1)部分的 O(2)消耗增加，而维生素 E 处理则加剧了这种增加。这种现象和维生素诱导的 M(1)蛋白恢复解释了先前报道的维生素 E 在寒冷暴露的大鼠肝脏中诱导整个线粒体群体呼吸增加的现象。
