Dépêche J, Sire O
Reprod Nutr Dev (1980). 1982;22(2):427-38. doi: 10.1051/rnd:19820314.
Rainbow trout testicular fragments were incubated at 8 different stages of the spermatogenetic cycle in the presence of tritiated progesterone or 17 alpha-hydroxyprogesterone. This paper describes the potential enzymatic activities involved in the delta 4 route leading to the production of "major" derivatives. 1) A 5-reductase converted progesterone into 5 alpha (beta)-pregnane-3,20-dione. 2) A 20 beta-oxydoreductase converted 17 alpha-hydroxyprogesterone into 17 alpha-hydroxy-20 beta-dihydroprogesterone. At some stages this synthesis reached or exceeded androgen production. 3) 20 beta-oxydoreductase, 17-20 desmolase and 17 beta-oxydoreductase are proposed as putative enzymatic steps in the regulation and modulation of steroidogenic metabolism in the trout testis. 4) The physiological role of the different major steroids synthesized by the testis in vitro is discussed, and the hypothesis of the involvement of 17 alpha-hydroxy-20 beta-dihydroprogesterone in the control of germ cell mitotic activity and/or feedback on the hypothalamo-pituitary system is examined.
虹鳟鱼睾丸组织片段在精子发生周期的8个不同阶段，于含有氚标记孕酮或17α-羟孕酮的条件下进行孵育。本文描述了参与导致“主要”衍生物产生的δ4途径的潜在酶活性。1）一种5-还原酶将孕酮转化为5α（β）-孕烷-3,20-二酮。2）一种20β-氧化还原酶将17α-羟孕酮转化为17α-羟基-20β-二氢孕酮。在某些阶段，这种合成达到或超过雄激素的产生量。3）20β-氧化还原酶、17-20裂链酶和17β-氧化还原酶被认为是鳟鱼睾丸中类固醇生成代谢调控和调节过程中的假定酶促步骤。4）讨论了睾丸体外合成的不同主要类固醇的生理作用，并研究了17α-羟基-20β-二氢孕酮参与控制生殖细胞有丝分裂活性和/或对下丘脑-垂体系统的反馈作用的假说。
