Bidey S P, Marshall N J, Ekins R P
Acta Endocrinol (Copenh). 1982 Nov;101(3):359-64. doi: 10.1530/acta.0.1010359.
The thyrotrophin (TSH)-dependent and time-related release of cyclic AMP has been characterised in primary monolayer cultures of normal human thyroid cells. Accumulation of cyclic AMP within the incubation medium was detectable within 1 h of exposure of cultures to 5 mU TSH/ml, and increased throughout of subsequent 15 h incubation period, final levels attained being consistently in excess of the corresponding intracellular cyclic AMP levels. Accumulation of cyclic AMP in the incubation medium was dependent on TSH dose, for both short (1 h) and prolonged (16 h) incubations. Moreover, after incubation for 16 h, cyclic AMP levels in the incubation medium were significantly (P less than 0.01) in excess of intracellular levels for each dose of TSH tested above 0.2 mU/ml. In the absence of TSH, accumulation of cyclic AMP in the incubation medium remained low, after both 1 h and 16 h incubation periods. A consideration of these observations suggests that a bioassay based upon the cyclic AMP content of incubation medium samples should provide a more precise detection system for thyroid stimulators than those measuring the intracellular cyclic AMP response, and this has been demonstrated for a cell preparation in which the intracellular response to TSH was minimal.
在正常人甲状腺细胞的原代单层培养物中，已对促甲状腺激素（TSH）依赖性和时间相关的环磷酸腺苷（cAMP）释放进行了表征。将培养物暴露于5 mU TSH/ml后1小时内，即可检测到孵育培养基中环磷酸腺苷的积累，并且在随后的15小时孵育期内持续增加，最终达到的水平始终超过相应的细胞内环磷酸腺苷水平。无论是短期（1小时）还是长期（16小时）孵育，孵育培养基中环磷酸腺苷的积累均依赖于TSH剂量。此外，孵育16小时后，对于测试的每种高于0.2 mU/ml的TSH剂量，孵育培养基中的环磷酸腺苷水平均显著（P<0.01）超过细胞内水平。在无TSH的情况下，孵育1小时和16小时后，孵育培养基中环磷酸腺苷的积累均保持在低水平。对这些观察结果的考虑表明，基于孵育培养基样品中环磷酸腺苷含量的生物测定法应比那些测量细胞内环磷酸腺苷反应的方法提供更精确的甲状腺刺激物检测系统，并且这已在细胞内对TSH反应最小的细胞制剂中得到证实。
