Horrum M A, Tobin R B, Ecklund R E
Department of Internal Medicine, College of Medicine, University of Nebraska Medical Center, Omaha.
Mol Cell Biochem. 1991 Apr 24;103(1):9-13. doi: 10.1007/BF00229588.
In order to further investigate the mechanisms regulating the control of mitochondrial respiration by thyroid hormone, the proton motive force was measured during State IV respiration in liver mitochondria isolated from euthyroid, hyperthyroid, hypothyroid and T3-treated hypothyroid rats. The proton motive force was significantly higher in the hyperthyroid group due to an increased delta pH. The proton motive force of hypothyroid mitochondria was lower than controls due to a decreased membrane potential. The proton motive force for the T3-treated hypothyroid group did not differ from the euthyroid group due to negating changes in the pH gradient and the membrane potential. The intramitochondrial volume was decreased in the hyperthyroid group and unchanged in the other groups. The results indicate that the thyroid status alters the proton motive force in State IV through individual changes in the pH and membrane potential components of the force. The component that changes in hyperthyroid mitochondria is different from that changing in hypothyroid mitochondria.
为了进一步研究甲状腺激素调节线粒体呼吸控制的机制，我们测定了从甲状腺功能正常、甲状腺功能亢进、甲状腺功能减退以及经三碘甲状腺原氨酸（T3）治疗的甲状腺功能减退大鼠分离出的肝线粒体在呼吸状态IV时的质子动力势。由于ΔpH升高，甲状腺功能亢进组的质子动力势显著更高。由于膜电位降低，甲状腺功能减退线粒体的质子动力势低于对照组。经T3治疗的甲状腺功能减退组的质子动力势与甲状腺功能正常组无差异，这是因为pH梯度和膜电位的变化相互抵消。甲状腺功能亢进组的线粒体内体积减小，其他组则无变化。结果表明，甲状腺状态通过改变质子动力势中pH和膜电位成分的个体变化来改变呼吸状态IV时的质子动力势。甲状腺功能亢进线粒体中发生变化的成分与甲状腺功能减退线粒体中变化的成分不同。
