Versloot P M, Schröder-van der Elst J P, van der Heide D, Boogerd L
Department of Human and Animal Physiology, Agricultural University, Wageningen, The Netherlands.
Am J Physiol. 1997 Dec;273(6):E1121-6. doi: 10.1152/ajpendo.1997.273.6.E1121.
Iodide uptake by the thyroid is an active process. Iodine deficiency and pregnancy are known to influence thyroid hormone metabolism. The aim of this study was to clarify the effects of iodine deficiency and pregnancy on iodide uptake by the thyroid. Radioiodide was injected intravenously into nonpregnant and 19-day pregnant rats receiving a normal or marginally iodine-deficient diet. The uptake of radioiodide by the thyroid was measured continuously for 4 h. The absolute iodide uptake by the maternal and fetal thyroid glands at 24 h was calculated by means of the urinary specific activity. Pregnancy resulted in a decrease in the absolute thyroidal iodide uptake. Marginal iodine deficiency had no effect on the absolute iodide uptake by the maternal thyroid. The decreased plasma inorganic iodide was compensated by an increase in thyroidal clearance. A similar compensation was not found for the fetus; the uptake of iodide by the fetal thyroid decreased by 50% during marginal iodine deficiency. This can lead to diminished thyroid hormone production, which will have a negative effect on fetal development, especially of the brain.
甲状腺对碘化物的摄取是一个活跃的过程。已知碘缺乏和妊娠会影响甲状腺激素代谢。本研究的目的是阐明碘缺乏和妊娠对甲状腺摄取碘化物的影响。将放射性碘化物静脉注射到接受正常或轻度碘缺乏饮食的未孕大鼠和妊娠19天的大鼠体内。连续4小时测量甲状腺对放射性碘化物的摄取。通过尿比活度计算母体和胎儿甲状腺在24小时时的绝对碘摄取量。妊娠导致甲状腺绝对碘摄取量减少。轻度碘缺乏对母体甲状腺的绝对碘摄取没有影响。血浆无机碘的降低通过甲状腺清除率的增加得到补偿。在胎儿中未发现类似的补偿情况；在轻度碘缺乏期间，胎儿甲状腺对碘化物的摄取减少了50%。这可能导致甲状腺激素产生减少，这将对胎儿发育，尤其是大脑发育产生负面影响。
