Andersson T, Rafter J
Department of Zoophysiology, University of Göteborg, Sweden.
Gen Comp Endocrinol. 1990 Jul;79(1):130-5. doi: 10.1016/0016-6480(90)90096-5.
In the present study on male rainbow trout, well-defined microsomal fractions from gonad, trunk kidney, and head kidney were used to study enzymes active on progesterone. The metabolites produced were identified by mass spectrometric analysis. In the testis the main metabolite was 17 alpha-hydroxyprogesterone which is an intermediate in the steroid biosynthetic pathway. 17 alpha-Hydroxyprogesterone was also identified in incubations from head and trunk kidney. The 17 alpha-hydroxylase activity was higher in the head kidney than in the trunk kidney which probably reflects the presence of steroid producing interrenal cells in this part of the kidney. The conversion of progesterone to 17 alpha-hydroxylated products in the testis and head kidney was NADPH dependent and inhibited by carbon monoxide, indicating the participation of cytochrome P450 monooxygenase in this reaction. NADH supported the reaction to some extent (27% of the NADPH-dependent activity) in the testis but not in the head kidney. In addition to 17 alpha-hydroxyprogesterone the head and trunk kidney microsomes gave rise to 16 alpha- and 6 beta-hydroxyprogesterone. These activities were low or absent in testis microsomes. Progesterone 5 alpha-reductase activity was only detected in trunk kidney microsomes.
在本项针对雄性虹鳟鱼的研究中，来自性腺、躯干肾和头肾的明确微粒体组分被用于研究对孕酮有活性的酶。通过质谱分析鉴定所产生的代谢产物。在睾丸中，主要代谢产物是17α-羟基孕酮，它是类固醇生物合成途径中的一种中间体。在头肾和躯干肾的孵育物中也鉴定出了17α-羟基孕酮。头肾中的17α-羟化酶活性高于躯干肾，这可能反映了该部分肾脏中存在产生类固醇的肾上腺皮质细胞。睾丸和头肾中孕酮向17α-羟基化产物的转化依赖于NADPH，并受到一氧化碳的抑制，表明细胞色素P450单加氧酶参与了该反应。NADH在睾丸中对该反应有一定程度的支持作用（为NADPH依赖性活性的27%），但在头肾中则不然。除了17α-羟基孕酮外，头肾和躯干肾微粒体还产生了16α-和6β-羟基孕酮。这些活性在睾丸微粒体中较低或不存在。孕酮5α-还原酶活性仅在躯干肾微粒体中检测到。
