成骨样细胞MG-63中的甲状腺激素受体Ⅰ——细胞核可溶性甲状腺激素受体与激素（T3）结合的动力学

The thyroid hormone receptor in human osteogenic sarcoma cell line MG-63 cell --T3 binding studies with nuclear extracts

建立人类成骨样细胞系MG-63中甲状腺激素受体的结合实验的方法，测定受体动力学参数。体外培养MG-63细胞，制备细胞核提取液，对其细胞核提取物中的甲状腺激素受体与激素（主要是T3）结合的动力学进行了Seatchard分析。MG-63细胞核内存在高亲和力（Ka为7．68×10^9L／mol）和有限结合容量的甲状腺激素受体，最大结合容量为（111．25±10．73）fmol／mg蛋白。建立了一个简易的自培养细胞制备纯净细胞核的方法，为进一步研究成骨样细胞及骨组织中的甲状腺激素受体奠定基础。

[ Summary ] To establish a method for radioligand binding assay of thyroid hormone receptors （TR） in human osteoblast-like osteosarcoma cell line MG-63 and to estimate the kinetic parameters of putative receptors. The MG-63 cell was cultured in Ham＇s F12, the soluble TR was prepared from the intact nuclear extracts. The binding properties between TR and T3 were performed by using the traditional Scatchard analysis. The apparent Ka of TR in MG-63 is 7.68 × 10^9 L/mol, and MBC （ 111.25± 10.77 ） fmol/mg protein. The study indicated that MG-63 cells possessed high affinity and limited-capacity of TR in its nuclear extracts. This may serve as the starting and basic work about TR in bone cell.