THYROID HORMONES-CELL INTERACTIONS

甲状腺激素向骨骼肌细胞转运的机制 在两个系统中进行了研究，完整的大鼠比目鱼肌和连续 培养的大鼠成肌细胞（L 6 E9）。 在完整的肌肉中，L-T3的摄取是 胰岛素增强，胰岛素似乎通过Na+/H+交换剂起作用 系统 在成肌细胞中，研究了L-T3向细胞核的转运 与D-T3相比，显示受立体特异性 机制可能位于质膜。 它还显示， 使用特异性抑制剂，即T3从血浆转移到 细胞核是温度依赖性的，需要能量和完整的 细胞骨架结构，并可能是通过介导的内吞 通路 这些结果进一步表明，甲状腺激素的摄取， 细胞可能处于代谢控制之下。

The mechanism of transport of thyroid hormones into skeletal muscle cells was studied in two systems, the intact rat soleus muscle and continuously cultured rat myoblasts (L6E9). In intact muscle, uptake of L-T3 was enhanced by insulin, which appeared to act through the Na+/H+ exchanger system. In myoblasts, transport of L-T3 to cell nuclei was investigated and shown, by comparison with D-T3, to be regulated by a stereospecific mechanism probably located at the plasma membrane. It was also shown, by the use of specific inhibitors, that the transfer of T3 from plasma to the cell nucleus is temperature dependent, requires energy and an intact cytoskeletal architecture, and is probably mediated through an endocytotic pathway. These results indicate further that thyroid hormone uptake into cells may be under metabolic control.