Kwan T K, Taylor N F, Watson D, Gower D B
Biochem J. 1985 May 1;227(3):909-16. doi: 10.1042/bj2270909.
Microsomal fractions obtained from testes of 3-week-old piglets have been incubated, separately, with progesterone, 17-hydroxyprogesterone, 5-pregnene-3 beta,20 beta-diol, 16 alpha-hydroxypregnenolone, 5-androstene-3 beta,17 alpha-diol and dehydro-epiandrosterone. The metabolites, after derivatization, have been separated by capillary gas chromatography and identified by mass spectrometry. Quantification was by selected ion monitoring. Progesterone was shown to be 17-hydroxylated and also converted into 4,16-androstadien-3-one (androstadienone). The major metabolite of 17-hydroxyprogesterone was 4-androstene-3,17-dione (4-androstenedione), but little, if any, androstadienone was formed, indicating that this particular biosynthesis did not require 17-hydroxylation. The metabolites of 5-pregnene-3 beta, 20 beta-diol were found to be 17-hydroxypregnenolone, 3 beta-hydroxy-5,16-pregnadien-20-one (16-dehydropregnenolone) and 5,16-androstadien-3 beta-ol. Dehydroepiandrosterone and 5-androstene-3 beta,17 alpha-diol were interconvertible but neither steroid acted as a substrate for 16-androstene formation. However, dehydroepiandrosterone was metabolized to a small quantity of 4-androstenedione. Under the conditions used, no metabolites of 16 alpha-hydroxypregnenolone could be detected. The present results, together with those obtained earlier, indicate that the neonatal porcine testis has the capacity to synthesize weak androgens, mainly by the 4-en-3-oxo steroid pathway. Although 16-androstenes cannot be formed from C19 steroids, progesterone served as a substrate and may be converted directly to androstadienone, without being 17-hydroxylated first. The pathway to 5,16-androstadien-3 beta-ol, however, involves 17-hydroxypregnenolone and 16-dehydropregnenolone as intermediates.
从3周龄仔猪睾丸中获得的微粒体部分已分别与孕酮、17 - 羟孕酮、5 - 孕烯 - 3β,20β - 二醇、16α - 羟孕烯醇酮、5 - 雄烯 - 3β,17α - 二醇和脱氢表雄酮一起孵育。代谢产物经衍生化后，通过毛细管气相色谱法分离并通过质谱法鉴定。定量采用选择离子监测。结果表明，孕酮被17 - 羟化，还转化为4,16 - 雄二烯 - 3 - 酮（雄二烯酮）。17 - 羟孕酮的主要代谢产物是4 - 雄烯 - 3,17 - 二酮（4 - 雄烯二酮），但几乎没有形成雄二烯酮，这表明这种特定的生物合成不需要17 - 羟化。5 - 孕烯 - 3β,20β - 二醇的代谢产物被发现是17 - 羟孕烯醇酮、3β - 羟基 - 5,16 - 孕二烯 - 20 - 酮（16 - 脱氢孕烯醇酮）和5,16 - 雄二烯 - 3β - 醇。脱氢表雄酮和5 - 雄烯 - 3β,17α - 二醇可相互转化，但这两种甾体都不是16 - 雄烯形成的底物。然而，脱氢表雄酮代谢生成少量的4 - 雄烯二酮。在所使用的条件下，未检测到16α - 羟孕烯醇酮的代谢产物。目前的结果与早期获得的结果一起表明，新生猪睾丸有能力主要通过4 - 烯 - 3 - 氧代甾体途径合成弱雄激素。虽然不能从C19甾体形成16 - 雄烯，但孕酮可作为底物，可能直接转化为雄二烯酮，而无需先进行17 - 羟化。然而，通往5,16 - 雄二烯 - 3β - 醇的途径涉及17 - 羟孕烯醇酮和16 - 脱氢孕烯醇酮作为中间体。
