Kubota K, Uchimura H, Mitsuhashi T, Chiu S C, Kuzuya N, Nagataki S
Acta Endocrinol (Copenh). 1984 Jan;105(1):57-65. doi: 10.1530/acta.0.1050057.
Mice were infused continuously with graded doses of bovine TSH (bTSH) and changes in plasma concentrations of bTSH and T4 were measured. Then mice infused with 100 mU TSH per day were sacrificed on days 0, 1, 3 and 5 and their thyroids were excised to determine in vitro secretion of T4, T3 and rT3 during 3 h of incubation. At the end of the incubation, thyroidal contents of T4, T3 and rT3 were also determined after pronase digestion. Plasma bTSH levels were increased on day 1 to a level of 110 microU/ml and remained unchanged thereafter. Plasma T4 concentrations increased approximately 2-fold on day 1, but decreased to initial levels on days 3 and 5. Changes in T4 secretion in vitro paralleled those in plasma T4 concentrations; T4 secretion increased 2-fold on day 1, and decreased to the pre-TSH levels on days 3 and 5. In contrast, T3 secretion increased throughout the experimental period. The T3/T4 ratio in thyroidal secretion in vitro was the same as that in thyroidal contents on days 0 and 1 of TSH infusion, but the former was significantly greater than the latter on days 3 and 5. PTU (5.9 X 10(-5) M), a known inhibitor of T4 deiodination, added to the incubation media did not affect T4 secretion on days 0 and 1, but increased T4 secretion on days 3 and 5 to the level of day 1, but did not affect T3 secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
给小鼠持续输注不同剂量的牛促甲状腺激素（bTSH），并测定血浆中bTSH和T4浓度的变化。然后，每天输注100 mU TSH的小鼠在第0、1、3和5天被处死，切除其甲状腺以测定在3小时孵育期间T4、T3和反T3（rT3）的体外分泌。孵育结束后，经链霉蛋白酶消化后还测定了甲状腺中T4、T3和rT3的含量。血浆bTSH水平在第1天升高至110微单位/毫升，此后保持不变。血浆T4浓度在第1天增加约2倍，但在第3天和第5天降至初始水平。T4的体外分泌变化与血浆T4浓度变化平行；T4分泌在第1天增加2倍，在第3天和第5天降至TSH注射前水平。相比之下，T3分泌在整个实验期间均增加。在TSH输注的第0天和第1天，甲状腺体外分泌中的T3/T4比值与甲状腺含量中的相同，但在第3天和第5天，前者显著大于后者。添加到孵育培养基中的已知T4脱碘抑制剂丙硫氧嘧啶（PTU，5.9×10⁻⁵ M）在第0天和第1天不影响T4分泌，但在第3天和第5天将T4分泌增加到第1天的水平，且不影响T3分泌。（摘要截短至250字）
