Massa R, Sharp P J
J Endocrinol. 1981 Feb;88(2):263-9. doi: 10.1677/joe.0.0880263.
The metabolism in vitro of [4-14C]testosterone to reduced derivatives was studied in the pituitary gland, hypothalamus and hyperstriatum dorsale of cockerels from hatch to sexual maturity. The most important metabolites were 5 beta-dihydrotestosterone (5 beta-DHT), 5 beta-androstane-3 alpha, 17 beta-diol (5 beta-3 alpha-diol) and 5 beta-androstane-3 beta, 17 beta-diol. Trace amounts of androstenedione and, in the hypothalamus only, of 5 alpha-DHT were also detected. The amounts of 5 beta-reduced metabolites produced by all neuroendocrine tissues declined progressively during maturation with the steepest fall occurring during the first 2 weeks after hatch. At all ages studied, 5 beta-DHT was formed to the greatest extent by the hyperstriatum dorsale, to a lesser extent by the hypothalamus and in the smallest quantities by the pituitary gland. In the three tissues studied, 5 beta-3 alpha-diol tended to be formed to the greatest extent by the pituitary gland. No significant change was observed in the metabolism of testosterone to reduced derivatives in any of the neuroendocrine tissues after castration. It was concluded that in the cockerel, unlike the rat, a change in 5 alpha-reductase activity of the neuroendocrine tissues is unlikely to be involved in the initiation of puberty. The physiological significance of 5 beta-reductase activity in the neuroendocrine tissues remains to be established.
研究了从孵化到性成熟的公鸡垂体、下丘脑和背侧上纹状体中[4-¹⁴C]睾酮体外代谢为还原衍生物的情况。最重要的代谢产物是5β-二氢睾酮（5β-DHT）、5β-雄甾烷-3α,17β-二醇（5β-3α-二醇）和5β-雄甾烷-3β,17β-二醇。还检测到微量的雄烯二酮，且仅在下丘脑中检测到5α-DHT。所有神经内分泌组织产生的5β-还原代谢产物的量在成熟过程中逐渐下降，在孵化后的前2周下降最为明显。在所有研究的年龄段，背侧上纹状体形成5β-DHT的程度最大，下丘脑形成的程度较小，垂体形成的量最少。在所研究的三种组织中，垂体形成5β-3α-二醇的程度往往最大。阉割后，任何神经内分泌组织中睾酮代谢为还原衍生物的过程均未观察到显著变化。得出的结论是，与大鼠不同，公鸡神经内分泌组织中5α-还原酶活性的变化不太可能参与青春期的启动。神经内分泌组织中5β-还原酶活性的生理意义仍有待确定。
