Unger J, Boeynaems J M, Ketelbant-Balasse P, Dumont J E, Mockel J
Endocrinology. 1978 Nov;103(5):1597-604. doi: 10.1210/endo-103-5-1597.
The time sequence of radioiodine sequestration and secretion (BE131I) have been compared in dog thyroid slices prelabeled with 131I in vivo and incubated in vitro with or without TSH. Sequestration has been taken to be the amount of radioiodine present in phagocytic vacuoles or colloid droplets; the TSH or (Bu)2cAMP stimulation of the basal values was suppressed by endocytosis blocking drugs. TSH induced a sequestrated radioactivity (S) after 5 min and a stimulated secretion after 20 min. The secretion rate was constant: 1%/h (mean +/- SD = 1.0 +/- 0.4; n = 7) of the total radioactivity of the slices. At equilibrium, S was constant and equal to less than 1% of the total radioactivity. The half-life of S, assuming a disappearance rate proportional to S, was 26 min (26 +/- 4; n = 5); assuming a disappearance rate independent of S, the lifetime was 44 min (44 +/- 7; n = 6). At the steady state, the limiting step of maximally stimulated secretion was the hydrolysis of the sequestrated radioactivity and endocytosis rate was equal to secretion rate. Without TSH, a constant BEI release (0.23% +/- 0.07%/h; n = 7), insensitive to cytochalasin B, was observed, which corresponded to basal secretion.
对在体内用¹³¹I预先标记并在体外添加或不添加促甲状腺激素（TSH）孵育的犬甲状腺切片中放射性碘的摄取和分泌（¹³¹I）的时间序列进行了比较。摄取被视为吞噬泡或胶体滴中存在的放射性碘的量；内吞作用阻断药物抑制了TSH或（Bu）₂cAMP对基础值的刺激。TSH在5分钟后诱导摄取的放射性（S），并在20分钟后刺激分泌。分泌速率恒定：切片总放射性的1%/小时（平均值±标准差 = 1.0±0.4；n = 7）。在平衡时，S恒定且等于总放射性的不到1%。假设消失速率与S成比例，S的半衰期为26分钟（26±4；n = 5）；假设消失速率与S无关，寿命为44分钟（44±7；n = 6）。在稳态下，最大刺激分泌的限速步骤是摄取的放射性的水解，内吞速率等于分泌速率。在没有TSH的情况下，观察到恒定的¹³¹I释放（0.23%±0.07%/小时；n = 7），对细胞松弛素B不敏感，这对应于基础分泌。
