Effect of thyroidectomy on the kinetics of ADP-ATP translocation in liver mitochondria.
Effect of thyroidectomy on the kinetics of ADP-ATP translocation in liver mitochondria.
复制标题
甲状腺切除术对肝线粒体 ADP-ATP 易位动力学的影响。
DOI：
10.1016/0003-9861(83)90298-9
复制
发表时间：
1983
影响因子：
3.9
通讯作者：
Elson,CE
中科院分区：
文献类型：
--
作者：
Mak,IT;Shrago,E;Elson,CE
腺嘌呤核苷酸移位酶（AdNT）在甲状腺功能减退症氧化代谢减少中的作用已被研究。甲状腺切除大鼠肝线粒体的AdNT和呼吸活性均低于正常值30%。线粒体AdNT活性通过Pfaff和Klingenberg（Eur. 6，66，1968）。该酶的Km和Vmax具有温度依赖性。在生理温度下，正常大鼠AdNT的Km和Vmax分别为10 μm（对于外源性ADP）和4.73%s-1（标记腺嘌呤核苷酸的流出百分比）。在0 ~ 37 °C温度范围内，AdNT在甲减大鼠肝线粒体中的Vmax降低25-35%，Km升高75%。Dixonplot研究表明，甲状腺功能减退症患者的AdNT对丙戊酸盐和棕榈酰辅酶A抑制剂的敏感性高2 - 3倍。相反，甲状腺功能减退症患者的ADP-ATP移位酶比对照携带者对邦格列卡酯抑制更具抵抗力。ADP转运的减少与甲状腺功能减退症相关的氧化活性降低一致，显然是继线粒体内膜脂质基质变化之后发生的（F. L. Hoch（1977）Arch.Biochem.Biopolymer.178，535.）。
The role of adenine nucleotide translocase (AdNT) in the reduced oxidative metabolism of hypothyroidism has been examined. Both AdNT and respiratory activities in liver mitochondria of thyroidectomized rats were 30% below normal. Mitochondrial AdNT activities were determined by the back-exchange method of Pfaff and Klingenberg (Eur. J. Biochem.6, 66, 1968). TheKmandVmaxof the enzyme were temperature dependent. At physiological temperature, theKmandVmaxof the normal rat AdNT were 10 μm(for external ADP) and 4.73%s−1(percentage efflux of the labeled adenine nucleotides), respectively. AdNT in hypothyroid rat liver mitochondria exhibited a 25–35% lowerVmaxand 75% higherKmwhen assayed over the temperature range 0 to 37 °C. Dixonplot studies indicated that the AdNT in hypothyroidism was two- to threefold more sensitive to atractylate and palmitoyl-CoA inhibitions. In contrast the ADP-ATP translocase in hypothyroidism was more resistant than the control carrier to bongkrekate inhibition. The decrease in the transport of ADP, which is consistent with the decreased oxidative activity associated with hypothyroidism, apparently occurs secondary to changes in the lipid matrix of the inner mitochondrial membrane (F. L. Hoch (1977)Arch. Biochem. Biophys.178,535.).