Decreased serum triiodothyronine in starving rats is due primarily to diminished thyroidal secretion of thyroxine.
Decreased serum triiodothyronine in starving rats is due primarily to diminished thyroidal secretion of thyroxine.
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饥饿大鼠血清三碘甲状腺原氨酸降低主要是由于甲状腺分泌的甲状腺素减少。
DOI：
10.1172/jci111821
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Oppenheimer,JH
中科院分区：
文献类型：
--
作者：
Kinlaw,WB;Schwartz,HL;Oppenheimer,JH
尽管饥饿大鼠肝匀浆中甲状腺素（T4）5 '-脱碘酶活性降低，但关于饥饿对完整大鼠中T4向三碘甲状腺原氨酸（T3）净转化的影响，尚无可用信息。澄清这种关系似乎很重要，因为大鼠肝匀浆被广泛用作研究慢性病和热量剥夺患者循环T3减少的因素的模型。相反，预期的选择性降低循环T3水平在热量限制的人由于减少T4 T3转换，5天的饥饿的两组雄性Sprague-Dawley大鼠导致，矛盾的是，在一个更大的减少血清T4比血清T3水平。动力学研究表明，饥饿与T3的代谢清除率（MCR）没有变化有关，T4的MCR增加了20%，T4的周转率降低了67%，但T3的周转率仅降低了58%。此外，在研究的第一组大鼠中，注射125 I-T4后对全身匀浆的同位素组成进行的直接色谱分析表明，对照大鼠中21.8%的T4转化为T3，饥饿大鼠中28.8%转化为T3，这表明饥饿大鼠和对照大鼠中几乎所有的甲状腺外T3都来自T4的外周转化，甲状腺很少或没有直接分泌T3。我们的研究结果有力地指出，甲状腺分泌T4减少是观察到的循环T3减少的主要原因。由于机制，导致血浆T3水平降低，在人类和大鼠不同，它可能是重要的是重新检查使用肝匀浆制剂作为模型的发病机制的研究“低T3综合征”在人类。
Although thyroxine (T4) 5'-deiodinase activity is diminished in liver homogenates of starved rats, no information is available regarding the effect of starvation on net T4 to triiodothyronine (T3) conversion in the intact rat. It appeared important to clarify this relationship since rat liver homogenates are widely used as a model for the study of the factors responsible for reduced circulating T3 in chronically ill and calorically deprived patients. In contrast to the expected selective decrease in circulating T3 levels in calorically restricted humans due to diminished T4 to T3 conversion, 5 d of starvation of two groups of male Sprague-Dawley rats resulted, paradoxically, in a greater decrease in serum T4 than in serum T3 levels. Kinetic studies show that starvation is associated with no change in the metabolic clearance rate (MCR) of T3, a 20% increase in the MCR of T4, a 67% reduction in turnover rate of T4, but only a 58% reduction in the turnover rate of T3. Moreover, in the first group of rats studied, direct chromatographic analysis of the isotopic composition of total body homogenates after the injection of 125I-T4 showed that 21.8% of T4 is converted to T3 in control rats and 28.8% in starved rats, suggesting that virtually all extrathyroidal T3 in starved and control rats is derived from the peripheral conversion of T4, and that there is little or no direct thyroidal secretion of T3. Our findings strongly point to a reduced thyroidal secretion of T4 as the primary cause of the observed reduction in circulating T3. Since the mechanisms leading to reduced levels of plasma T3 differ in humans and rats, it may be important to reexamine the use of liver homogenate preparations as models for study of the pathogenesis of the "low T3 syndrome" in humans.
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决定饥饿大鼠中 3,5,3-三碘甲状腺原氨酸反应性肝酶活性水平的因素。
影响因子：
4.8
作者：
Oppenheimer,JH;Schwartz,HL
通讯作者：
Schwartz,HL
甲状腺功能正常和甲状腺功能减退大鼠甲状腺外三碘甲状腺原氨酸生成途径的定性和定量差异。
DOI：
10.1172/jci111313
发表时间：
1984
期刊：
The Journal of clinical investigation
影响因子：
--
作者：
Silva,JE;Gordon,MB;Crantz,FR;Leonard,JL;Larsen,PR
通讯作者：
Larsen,PR
原位灌注测定大鼠甲状腺分泌的碘化成分的定量研究。
影响因子：
4.8
作者：
Kenjiro Inoue;Yvonne Grimm;Monte A. Greer
通讯作者：
Monte A. Greer
血浆 L-三碘甲状腺原氨酸的新放射免疫测定法：甲状腺疾病和维持激素替代的患者的测量。
影响因子：
15.9
作者：
M. Surks;A. R. Schadlow;J. Oppenheimer
通讯作者：
J. Oppenheimer
大鼠体内 L-甲状腺素甲状腺外转化为 3,5,3-三碘-L-甲状腺氨酸的定量。
影响因子：
15.9
作者：
H. L. Schwartz;M. Surks;J. Oppenheimer
通讯作者：
J. Oppenheimer