Nakamura Y, Suzuki M, Kobayashi I, Shimomura Y, Kakegawa T
Endocrinol Jpn. 1976 Apr;23(2):157-63. doi: 10.1507/endocrj1954.23.157.
To assess a possible postmortem change in the level of cyclic AMP, the thyroids were snap-frozen at various time intervals after removal. Rats were fed a low-iodine diet (LID) with PTU for 2 weeks and a week after PTU discontinuation (PTU withdrawal). In all cases, the cyclic AMP level tended to increase as time elapsed from removing till fixing the thyroids, but in the PTU withdrawal group, the level was rapidly increased 2-fold after 5 min. In an acute experiment, the thyroids were removed under anesthesia and frozen rapidly. Intravenous administration of ovine thyrotropin (250 mU) and TRH (500 ng) brought about a rapid increase in the thyroidal level of cyclic AMP to 40% to 20% over the control level. Two weeks after PTU treatment, circulating thyrotropin was increased to a maximum of 19-fold and a further enhancement ("rebound") was observed after PTU withdrawal. PTU treatment led to an increase in the thyroidal level of cyclis AMP pre mug DNA to 60% over the control value. Following PTU withdrawal, the rise in the level of cyclic AMP returned to the normal level. However, there was no change in the concentration when it was expressed as per mg wet tissue weight. Therefore, the increase in the thyroidal concentration of cyclic AMP per mug of DNA may be due to an increase in volume of the follicular cells.
为评估环磷酸腺苷（cAMP）水平可能出现的死后变化，在切除甲状腺后的不同时间间隔将其速冻。大鼠喂食含丙硫氧嘧啶（PTU）的低碘饮食（LID）2周，并在停用PTU（PTU撤药）1周后进行实验。在所有情况下，从切除甲状腺到固定甲状腺的过程中，cAMP水平往往随着时间的推移而升高，但在PTU撤药组中，5分钟后该水平迅速升高至2倍。在急性实验中，在麻醉下切除甲状腺并迅速冷冻。静脉注射羊促甲状腺素（250 mU）和促甲状腺激素释放激素（TRH，500 ng）使甲状腺cAMP水平迅速升高，比对照水平高出40%至20%。PTU治疗2周后，循环促甲状腺素增加至最大值的19倍，并且在PTU撤药后观察到进一步增强（“反弹”）。PTU治疗导致每微克DNA的甲状腺环化AMP水平比对照值增加60%。PTU撤药后，cAMP水平的升高恢复到正常水平。然而，以每毫克湿组织重量表示时浓度没有变化。因此，每微克DNA的甲状腺cAMP浓度增加可能是由于滤泡细胞体积增加所致。
