Wallach S, Bellavia J V, Gamponia P J, Bristrim P
J Clin Invest. 1972 Jun;51(6):1572-7. doi: 10.1172/JCI106954.
The effect of L-thyroxine on the bidirectional transport of calcium and magnesium in rat liver was assessed in vitro. An increase of 34% in the fractional coefficient for calcium influx was observed 24 hr after the administration of 500 mug of thyroxine. Chronic treatment with thyroxine for 1 and 3 wk at a dose of 750 mug/wk resulted in increases in calcium influx of 57 and 51%, respectively. Calcium efflux was increased irregularly, by 14-26%. Magnesium transport measured in a similar system was not altered by 24 or 48 hr of treatment with thyroxine, but continuation of treatment for 1-3 wk resulted in increases in magnesium influx of 47-49%. Magnesium efflux was not significantly affected. Neither increased cellular binding of divalent cations nor enhanced protein synthesis could be incriminated in the stimulatory effect of thyroxine on divalent cation transport. Actinomycin-D and D,L-ethionine, inhibitors of protein synthesis, stimulated calcium and magnesium transport in liver independently of the effects of thyroxine. These data present the possibility that certain actions of thyroid hormone may be mediated or modulated by associated, direct changes in the cellular transport and intracellular concentrations of divalent cations.
在体外评估了L-甲状腺素对大鼠肝脏中钙和镁双向转运的影响。给予500微克甲状腺素24小时后，观察到钙流入分数系数增加了34%。以750微克/周的剂量用甲状腺素进行1周和3周的长期治疗，分别导致钙流入增加57%和51%。钙流出不规则增加，增加了14% - 26%。在类似系统中测量的镁转运在甲状腺素治疗24或48小时后未发生改变，但持续治疗1 - 3周导致镁流入增加47% - 49%。镁流出未受到显著影响。甲状腺素对二价阳离子转运的刺激作用既不能归咎于细胞中二价阳离子结合增加，也不能归咎于蛋白质合成增强。蛋白质合成抑制剂放线菌素-D和D,L-乙硫氨酸可独立于甲状腺素的作用刺激肝脏中的钙和镁转运。这些数据表明，甲状腺激素的某些作用可能由细胞转运和细胞内二价阳离子浓度的相关直接变化介导或调节。
