Decreased serum 3,5,3'-triiodothyronine (T3) and abnormal serum binding of T3 in calorie-deficient rats: adaptation after chronic underfeeding.
Decreased serum 3,5,3'-triiodothyronine (T3) and abnormal serum binding of T3 in calorie-deficient rats: adaptation after chronic underfeeding.
复制标题
热量缺乏大鼠血清 3,5,3-三碘甲状腺原氨酸 (T3) 降低和 T3 血清结合异常：长期喂养不足后的适应。
DOI：
10.1210/endo-118-6-2464
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发表时间：
1986
期刊：
影响因子：
4.8
通讯作者：
J. Anderson
中科院分区：
文献类型：
--
作者：
A. Glass;R. A. Young;J. Anderson
饥饿和低蛋白饮食喂养对大鼠血清甲状腺激素浓度和血清甲状腺激素结合蛋白有显著影响。我们研究了在另一种营养不良模型中是否可以看到类似的变化，即在不改变饮食组成的情况下喂养不足，特别是这种变化是否会在长期改变饮食（适应）后消失。将21日龄的雄性大鼠置于五个不同水平的正常组成的饮食摄入量（18%蛋白质，70%碳水化合物），并且在30、60或100天的喂养不足后，将来自每个饮食组的动物（n = 8-10）处死。经过30或60天的喂养不足，显着的直接相关性之间的生长速度（作为一个指标的喂养不足的程度）和血清T3（RIA），游离T3（平衡透析），和血清游离T3（T3 X游离T3百分比）。然而，当饥饿延长到100天，有没有生长率和百分比游离T3之间的相关性，而生长率和血清游离T3之间的相关性弱（r = 0.33）。当给予五种不同食物摄入水平的动物在三个体重里程碑而不是三个单独的年龄里程碑时被处死时，观察到了类似的质量变化。血清甲状腺结合蛋白的聚丙烯酰胺凝胶电泳显示，低百分比的游离T3在喂养不足的大鼠60天后看到的是与甲状腺结合球蛋白的发展，通常不会发现，但这已经消失了100天的喂养不足。我们的结论是，随着时间的推移，营养相关的血清甲状腺激素变量的变化显示适应。由于营养不良引起的血清甲状腺激素结合变化，在任何试验性治疗导致摄食量减少的研究中，血清甲状腺激素总浓度可能无法准确反映甲状腺状态。
Both starvation and feeding of a low protein diet have dramatic effects on serum thyroid hormone concentrations and on the serum binding proteins for thyroid hormones in rats. We examined whether similar changes might be seen in another model of undernutrition, namely underfeeding without alteration of dietary composition, and in particular whether such changes would disappear after prolonged alteration in diet (adaptation). Male rats aged 21 days were put on five different levels of intake of a diet of normal composition (18% protein, 70% carbohydrate), and animals from each dietary group (n = 8-10) were killed after 30, 60, or 100 days of underfeeding. After 30 or 60 days of underfeeding, significant direct correlations were observed between growth rate (used as an index of the degree of underfeeding) and serum T3 (RIA), percent free T3 (equilibrium dialysis), and serum free T3 (T3 X percent free T3). When underfeeding was prolonged to 100 days, however, there was no correlation between growth rate and percent free T3, while the correlation between growth rate and serum free T3 was weak (r = 0.33). Qualitatively similar changes were seen when animals given five different levels of food intake were killed at three body weight milestones rather than three separate age milestones. Polyacrylamide gel electrophoresis of serum thyroid-binding proteins revealed that the low percent free T3 in underfed rats seen after 60 days of underfeeding was associated with the development of a thyroid-binding globulin not normally found, but this had disappeared by 100 days of underfeeding. We conclude that nutrition-related changes in serum thyroid hormone variables show adaptation over time. Because of changes in serum binding of thyroid hormones caused by undernutrition, total serum thyroid hormone concentrations may not be an accurate reflection of thyroid status in any investigational study in which an experimental treatment leads to decreased food intake.