Pharmakiotis A D, Alexander W D
Endocrinology. 1975 May;96(5):1324-8. doi: 10.1210/endo-96-5-1324.
Repeated administration (every 8 h) of (35S) Propylthiouracil (PTU) resulted in gradual accumulation of unmetabolised PTU by the thyroid gland until the 9th dose was given. Subsequently a plateau-level was attained which was proportional to dose with the two dose levels used. During repeated administration once daily the intrathyroid concentration of free PTU varied markedly in the course of each 24-h period. Chromatographic analysis showed four compounds: PTU, sulphate and two unidentified compounds as well as origin material. The proportions of these compounds were different in the different dose studies. Thus, the ratio of compound Y/compound X was found to be inversely related to dose. The plasma 35S-radioactivity increased throughout the studies and was proportional to dose.
每8小时重复给药（35S）丙硫氧嘧啶（PTU），甲状腺会逐渐积累未代谢的PTU，直至给予第9剂。随后达到一个平台期水平，该水平与所使用的两个剂量水平成比例。每日重复给药期间，游离PTU的甲状腺内浓度在每个24小时周期内有明显变化。色谱分析显示有四种化合物：PTU、硫酸盐和两种未鉴定的化合物以及起始物质。在不同剂量研究中，这些化合物的比例不同。因此，发现化合物Y/化合物X的比例与剂量呈负相关。在整个研究过程中，血浆35S放射性增加，且与剂量成比例。
