Hogan S, Himms-Hagen J
Am J Physiol. 1981 Dec;241(6):E436-43. doi: 10.1152/ajpendo.1981.241.6.E436.
Lean and genetically obese (ob/ob): mice were treated daily for 2 wk with thyroxine (T4), noradrenaline, or thyroxine plus noradrenaline. T4 treatment of obese mice increased the abnormally low binding of GDP to brown adipose tissue mitochondria and permitted a cold-induced increase to occur. It also brought about a return to a more normal ultrastructure of the mitochondria of the obese mice. T4 treatment did not alter the binding of GDP to brown adipose tissue mitochondria of lean mice. The binding of GDP to brown adipose tissue mitochondria is known to be to a 32,000-dalton polypeptide associated with the thermogenic proton conductance pathway. T4 treatment did not alter the proportion of this polypeptide in the mitochondrial membrane in either lean or obese mice. Treatment with noradrenaline did not alter the binding of GDP to brown adipose tissue mitochondria in either lean or obese mice. The effect of T4 is thought to be due to an improvement in the defective responsiveness of brown adipose tissue to endogenous noradrenaline in the obese mice, known to be related to their poor cold resistance and obesity. The improvement allows a more normal noradrenaline-induced unmasking of GDP binding sites, both in response to diet and in response to cold. Such treatment is known to improve cold resistance of the obese mice, and this appears to be correlated with an improvement in the functioning of their defective brown adipose tissue.
瘦小鼠和遗传性肥胖（ob/ob）小鼠：每天用甲状腺素（T4）、去甲肾上腺素或甲状腺素加去甲肾上腺素处理2周。对肥胖小鼠进行T4处理可增加棕色脂肪组织线粒体中异常低的GDP结合，并使冷诱导的增加得以发生。它还使肥胖小鼠线粒体的超微结构恢复到更正常的状态。T4处理并未改变瘦小鼠棕色脂肪组织线粒体中GDP的结合。已知棕色脂肪组织线粒体中GDP的结合是与产热质子传导途径相关的一种32000道尔顿的多肽。T4处理在瘦小鼠或肥胖小鼠中均未改变该多肽在线粒体膜中的比例。用去甲肾上腺素处理在瘦小鼠或肥胖小鼠中均未改变棕色脂肪组织线粒体中GDP的结合。T4的作用被认为是由于肥胖小鼠棕色脂肪组织对内源性去甲肾上腺素的缺陷反应性得到改善，已知这与它们较差的耐寒性和肥胖有关。这种改善使得无论是对饮食还是对寒冷，去甲肾上腺素诱导的GDP结合位点的暴露更正常。已知这种处理可改善肥胖小鼠的耐寒性，这似乎与它们有缺陷的棕色脂肪组织功能的改善相关。
