Mak I T, Shrago E, Elson C E
Biochim Biophys Acta. 1983 Feb 17;722(2):302-9. doi: 10.1016/0005-2728(83)90077-4.
The decrease in respiration rate following thyroidectomy is preceded by changes in the lipid composition of the mitochondrial membrane (Hoch, F.L., Subramanian, C., Dhopeshwarkar, G.A. and Mead, J.F. (1981) Lipids 16, 328-334) and in concert, changes in the kinetic parameters of the adenine nucleotide translocase (Mak, I.T., Shrago, E. and Elson, C.E. (1981) Fed. Proc. 40, 398). To demonstrate that physiological adaptation also involves this sequence of events, rats were housed at 8 degrees C for 3-4 weeks. Cold adaptation resulted in a modest (5%) increase in the unsaturation index for the mitochondrial fatty acids comprised of a significant increase in arachidonic acid and a reciprocal decrease in linoleic acid. Phospholipid analysis indicated that cold adaptation increased the mitochondrial phosphatidylethanolamine and reciprocally decreased the phosphatidylcholine content. Concomitantly, cold adaptation resulted in 25-30% increases in rat liver mitochondrial respiratory activities without changing the respiratory control or ADP/O ratios. The kinetic parameters of the adenine nucleotide translocase were determined by the back-exchange method (Pfaff, E. and Klingenberg, M. (1968) Eur. J. Biochem. 6, 66-79). At 0-4 and 10 degrees C, the Vmax and Km of the cold-adapted rat liver adenine nucleotide translocase were not distinguishable from the control values. The Ki values determined by Dixon plot studies for atractylate and palmitoyl-CoA were also comparable between the two groups. However, at 25 and 37 degrees C, cold-adapted rat liver adenine nucleotide translocase exhibited a 20% increase in Vmax and a 20% decrease in Km for external ADP. The results suggest that one adaption to a cold environment involves hormone-mediated changes in the lipid composition in the mitochondrial membranes which in turn modulate the adenine nucleotide translocase and subsequent respiratory activities.
甲状腺切除术后呼吸速率的降低之前，线粒体膜的脂质组成会发生变化（霍赫，F.L.，苏布拉马尼亚姆，C.，德霍佩什瓦尔卡尔，G.A.和米德，J.F.（1981年）《脂质》16卷，328 - 334页），同时，腺嘌呤核苷酸转位酶的动力学参数也会发生变化（马克，I.T.，施拉戈，E.和埃尔森，C.E.（1981年）《联邦程序》40卷，398页）。为了证明生理适应也涉及这一系列事件，将大鼠饲养在8摄氏度环境中3 - 4周。冷适应导致线粒体脂肪酸的不饱和度指数适度增加（5%），其中花生四烯酸显著增加，亚油酸相应减少。磷脂分析表明，冷适应增加了线粒体磷脂酰乙醇胺含量，同时相应降低了磷脂酰胆碱含量。与此同时，冷适应使大鼠肝脏线粒体呼吸活性提高了25 - 30%，而呼吸控制率或ADP/O比值没有变化。腺嘌呤核苷酸转位酶的动力学参数通过反向交换法测定（普法夫，E.和克林根贝格，M.（1968年）《欧洲生物化学杂志》6卷，66 - 79页）。在0 - 4摄氏度和10摄氏度时，冷适应大鼠肝脏腺嘌呤核苷酸转位酶的Vmax和Km与对照值没有差异。通过狄克逊图研究确定的对阿特拉津和棕榈酰辅酶A的Ki值在两组之间也相当。然而，在25摄氏度和37摄氏度时，冷适应大鼠肝脏腺嘌呤核苷酸转位酶的Vmax增加了20%，对外源ADP的Km降低了20%。结果表明，对寒冷环境的一种适应涉及激素介导的线粒体膜脂质组成变化，进而调节腺嘌呤核苷酸转位酶及随后的呼吸活性。
