Thyroxine 5'-deiodinase in brown adipose tissue of myopathic hamsters.
Thyroxine 5'-deiodinase in brown adipose tissue of myopathic hamsters.
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肌病仓鼠棕色脂肪组织中的甲状腺素 5-脱碘酶。
DOI：
10.1152/ajpendo.1986.251.1.e8
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
J. Himms‐Hagen
中科院分区：
文献类型：
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作者：
J. Kopecký;L. Sigurdson;I. Park;J. Himms‐Hagen
肌病叙利亚仓鼠（BIO 14.6）的棕色脂肪组织（BAT）比正常人少。该组织对冷的营养反应小于正常，对饮食和光周期的营养反应不存在。目的是发现在它们的BAT中甲状腺素5 '-脱碘酶的活性是否在对冷的反应中正常地增加，从而是否内源性产生3，5，3'-三碘甲状腺原氨酸的缺陷可能是减弱的营养反应的基础。还研究了饲喂高脂饲料对5 ′-脱碘酶活性的影响。冷习服增加了肌病仓鼠BAT中甲状腺素5 '-脱碘酶的活性，但由于体积较小，总的甲状腺素5'-脱碘酶活性仍低于正常。冷诱导的线粒体解偶联蛋白浓度的增加也小于正常。血清3，5，3 '-三碘甲腺原氨酸水平在肌病仓鼠中较低，冷暴露或冷习服后仍低于正常。给肌病仓鼠喂食高脂饮食导致甲状腺素5 '-脱碘酶活性比正常仓鼠受到更大的抑制;蛋白质含量和线粒体解偶联蛋白浓度的正常增加不存在。我们的结论是，有缺陷的营养反应的BAT的肌病仓鼠是不是继发于其甲状腺素5 '-脱碘酶活性的调节缺陷，因为这种活动似乎并不必然与肥大的BAT。肌病仓鼠血清3，5，3 '-三碘甲腺原氨酸水平低可能继发于BAT外周甲状腺素脱碘能力降低。
Myopathic Syrian hamsters (BIO 14.6) have less brown adipose tissue (BAT) than normal. The trophic response of this tissue to cold is smaller than normal and trophic responses to diet and to photoperiod are absent. The objective was to find out whether activity of thyroxine 5'-deiodinase in their BAT was increased normally in response to cold and thus whether a defect in endogenous production of 3,5,3'-triiodothyronine might underlie the attenuated trophic response. The effect of feeding a high-fat diet on activity of 5'-deiodinase was also studied. Cold acclimation increased thyroxine 5'-deiodinase activity in BAT of the myopathic hamster, but the total remained smaller than normal because of the smaller size. The cold-induced increase in concentration of mitochondrial uncoupling protein was also smaller than normal. The level of serum 3,5,3'-triiodothyronine was low in myopathic hamsters and remained lower than normal when they were cold-exposed or cold acclimated. Feeding the high-fat diet to myopathic hamsters resulted in a greater than normal suppression of thyroxine 5'-deiodinase activity than in normal hamsters; the normal increases in protein content and in concentration of mitochondrial uncoupling protein were absent. We conclude that the defective trophic response of BAT of the myopathic hamster is not secondary to defective regulation of its thyroxine 5'-deiodinase activity because this activity does not appear to be obligatorily linked to hypertrophy of BAT. The low level of serum 3,5,3'-triiodothyronine in the myopathic hamster may be secondary to reduced capacity for peripheral thyroxine deiodination in its BAT.