Hodgins M B, Hay J B, Donnelly J B
J Endocrinol. 1982 Jun;93(3):403-13. doi: 10.1677/joe.0.0930403.
Human forehead skin incubated in vitro is known to metabolize testosterone to 17-oxosteroids faster than the reverse reaction, while axillary skin rapidly metabolizes androstenedione to 17 beta-hydroxysteroids, such as testosterone and 5 alpha-dihydrotestosterone. While this has been confirmed using a larger number of patients, some indication has been found that 17 beta-hydroxysteroid oxidoreductase activity declines with age in the axilla. The relative rates of 17 beta-oxidation and reduction (direction of operation of skin 17 beta-hydroxysteroid oxidoreductase activity) were not altered by variety of incubation conditions. Large amounts of a membrane-bound 17 beta-hydroxysteroid oxidoreductase, showing preference for NAD as coenzyme and testosterone (rather than androstenedione) as steroid substrate, were found in forehead skin from one patient. On the other hand, the main axillary skin enzyme in skin from another patient was soluble and showed preference for NADP and androstenedione. It is postulated that 17 beta-oxidation and reduction in skin is controlled by the relative amount, the coenzyme preferences and the kinetic properties of these two enzymes.
已知体外培养的人体前额皮肤将睾酮代谢为17 - 氧类固醇的速度比逆向反应更快，而腋窝皮肤则迅速将雄烯二酮代谢为17β - 羟基类固醇，如睾酮和5α - 双氢睾酮。虽然这已通过大量患者得到证实，但已发现一些迹象表明腋窝中17β - 羟基类固醇氧化还原酶活性会随年龄下降。17β - 氧化和还原的相对速率（皮肤17β - 羟基类固醇氧化还原酶活性的作用方向）不会因多种培养条件而改变。在一名患者的前额皮肤中发现了大量与膜结合的17β - 羟基类固醇氧化还原酶，该酶更倾向于以NAD作为辅酶，以睾酮（而非雄烯二酮）作为类固醇底物。另一方面，另一名患者皮肤中的主要腋窝皮肤酶是可溶性的，且更倾向于NADP和雄烯二酮。据推测，皮肤中的17β - 氧化和还原由这两种酶的相对含量、辅酶偏好和动力学特性控制。
