Regulation of thyrotropin production by mouse pituitary thyrotropic tumor cells in vitro by physiological levels of thyroid hormones.
Regulation of thyrotropin production by mouse pituitary thyrotropic tumor cells in vitro by physiological levels of thyroid hormones.
复制标题
甲状腺激素生理水平对体外小鼠垂体促甲状腺肿瘤细胞促甲状腺素产生的调节。
作者：
M. Gershengorn
从连续移植的小鼠垂体促甲状腺激素肿瘤的原代悬浮培养物被证明是由甲状腺激素的生理水平调节。TSH释放在对照培养物中线性长达48小时，在暴露于三碘甲腺原氨酸（T3）（4.0 nM）的培养物中10、24和48小时后逐渐受到抑制。TSH释放被抑制高达55%的控制和葡萄糖消耗刺激高达2.6倍，在剂量依赖性的方式由T3在0.2和4.0 nM之间。T3和甲状腺素（T4）和TSH产生的双相剂量依赖关系在两个系列的文化中得到证实。促甲状腺激素的生产刺激逐步T3高达0.1 nM和T4高达5 nM。在较高的T3和T4水平，TSH的生产进行性抑制。半数最大抑制发生在总培养基浓度为0.2 nM T3和15 nM T4或游离激素水平分别为8 x 10-12 M和14 X 10-11 M时。证明了T3和T4的高亲和力、低容量核结合位点。AP…
Primary suspension cultures from serially transplanted mouse pituitary thyrotropic tumors were shown to be regulated by physiological levels of thyroid hormones. TSH release was linear for up to 48 h in control cultures and was inhibited progressively after 10, 24, and 48 h in cultures exposed to triiodothyronine (T3), 4.0 nM. TSH release was inhibited up to 55% of control and glucose consumption was stimulated up to 2.6-fold in a dose-dependent fashion by T3 between 0.2 and 4.0 nM. A biphasic dose-dependent relationship for T3 and thyroxine (T4), and TSH production was demonstrated in two series of cultures. TSH production was stimulated progressively by T3 up to 0.1 nM and T4 up to 5 nM. At higher T3 and T4 levels, TSH production was progressively inhibited. Half-maximal inhibition occurred at total medium concentrations of 0.2 nM T3 and 15 nM T4 or free hormone levels of 8 x 10-12 M and 14 X 10-11 M, respectively. High affinity, low capacity nuclear binding sites were demonstrated for T3 and T4. The ap...