Horst H J, Erdmann T
Horm Metab Res. 1980 Oct;12(10):541-5. doi: 10.1055/s-2007-999194.
Short term castrated rats were sacrificed at different time intervals after oral administration of tritium labeled TU. Blood and organs were collected and measured for total radioactivity uptake. At the time of peak values of radioactivity the in vivo metabolite pattern was investigated by thin layer chromatography. In vitro studies were performed in plasma, muscle and prostate cytosol. The radioactivity uptake into plasma and prostate in vivo reached a first maximum 2 1/2 h after oral administration of TU. A second peak appeared after 5 h in the prostate. While only 16% of the total plasma radioactivity appeared in the non esterified fraction, the tissues contained 69-71%. In plasma, the bulbocavernosus/levator ani muscle and in the skeletal muscle, free testosterone was the main unesterified androgen (14-28%). Prostate and seminal vesicles contained primarily 5 alpha-DHT (47 and 34%, respectively). Further metabolites were found in the fractions of 17 beta-hydroxy-5 alpha-androstanediols, epiandrosterone, androsterone, 4-androstenedione and 5 alpha-androstanedione. After incubation in vitro with TU, prostate and muscle cytosol contained significant amounts (39% and 17%, respectively) of free androgens. It was concluded that peripheral organs as well as the prostate itself are capable of cleaving the undecanoic ester and that the biological action of TU is exerted by unesterified androgens which occur in a pattern similar to that obtained after i.v. injection of free testosterone.
给短期去势大鼠口服氚标记的TU后，在不同时间间隔处死动物。收集血液和器官并测量总放射性摄取量。在放射性达到峰值时，通过薄层色谱法研究体内代谢物模式。在血浆、肌肉和前列腺胞质溶胶中进行体外研究。口服TU后2.5小时，血浆和前列腺中的放射性摄取量首次达到最大值。前列腺在5小时后出现第二个峰值。虽然血浆总放射性中只有16%出现在非酯化部分，但组织中这一比例为69 - 71%。在血浆、球海绵体肌/提肛肌和骨骼肌中，游离睾酮是主要的非酯化雄激素（14 - 28%）。前列腺和精囊中主要含有5α - 双氢睾酮（分别为47%和34%）。在17β - 羟基 - 5α - 雄甾二醇、表雄酮、雄甾酮、4 - 雄烯二酮和5α - 雄甾烷二酮的部分中发现了其他代谢物。用TU进行体外孵育后，前列腺和肌肉胞质溶胶中含有大量游离雄激素（分别为39%和17%）。结论是外周器官以及前列腺本身都能够裂解十一烷酸酯，并且TU的生物学作用是由非酯化雄激素发挥的，其出现模式与静脉注射游离睾酮后相似。
