Reed H L, D'Alesandro M M, Kowalski K R, Homer L D
Thermal Stress Adaptation Program, Naval Medical Research Institute, Bethesda 20889-5055.
Am J Physiol. 1992 Jul;263(1 Pt 1):E85-93. doi: 10.1152/ajpendo.1992.263.1.E85.
The influence of cold exposure on triiodothyronine (T3) kinetics was studied in 16 men before, during (biweekly), and after 80 (10/wk) cold (4 degrees C) air exposures. We used serum values before and up to 24 h after a pharmacological oral (o) dose of T3 [76.8 nmol (50 micrograms)] to calculate noncompartmental kinetic parameters. To assess the role of thyroxine (T4) and thyrotropin (TSH), we administered a replacement dose of T3 [46.0 nmol/day (30 micrograms)] to eight men (+T3 group) and placebo to eight others (-T3 group) for the 2-mo study. There was no group effect of T3 treatment (+T3) on oral total volume of distribution (TVdo), metabolic clearance rate (MCRo), or disposal rate (DRo). TVdo was not changed over the study. Cold increased MCRo by 5.4 +/- 2.0 l.day-1.m-2. DRo increased with cold by 10.2 +/- 4.4 nmol.day-1.m-2. Although serum TSH, total T4, and free T4 decreased by approximately 50% in the +T3 group, the changes in MCRo and DRo with cold were not different from those in -T3. We describe that human T3 kinetics are changed with brief repeated exposures to cold air and that these increases in MCRo and DRo do not appear to be dependent on TSH or T4.
在16名男性中研究了冷暴露对三碘甲状腺原氨酸（T3）动力学的影响，研究时间为80次（每周10次）冷（4摄氏度）空气暴露之前、期间（每两周一次）和之后。我们使用口服药理学剂量的T3 [76.8纳摩尔（50微克）]之前及之后长达24小时的血清值来计算非房室动力学参数。为了评估甲状腺素（T4）和促甲状腺激素（TSH）的作用，在为期2个月的研究中，我们给8名男性（+T3组）服用T3替代剂量[46.0纳摩尔/天（30微克）]，给另外8名男性（-T3组）服用安慰剂。T3治疗（+T3）对口服总体分布容积（TVdo）、代谢清除率（MCRo）或处置率（DRo）没有组间效应。在研究过程中TVdo没有变化。寒冷使MCRo增加5.4±2.0升·天-1·米-2。DRo随寒冷增加10.2±4.4纳摩尔·天-1·米-2。尽管+T3组血清TSH、总T4和游离T4下降了约50%，但寒冷引起的MCRo和DRo变化与-T3组没有差异。我们描述了人类T3动力学在短期反复暴露于冷空气后会发生变化，并且MCRo和DRo的这些增加似乎不依赖于TSH或T4。
