Conley A J, Head J R, Stirling D T, Mason J I
Cecil H. and Ida Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, Cell Biology, University of Texas Southwestern Medical Center, Dallas 75235-9051.
Endocrinology. 1992 May;130(5):2641-50. doi: 10.1210/endo.130.5.1374010.
The expression of cholesterol side-chain cleavage cytochrome P450 (P450scc), 17 alpha-hydroxylase cytochrome P450 (P45017 alpha), and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) was studied in bovine placenta and fetal adrenal glands throughout gestation. The levels of expression of these enzymes were much lower in the placenta than in the adrenals by Western and Northern analyses. The levels of P450scc, however, remained relatively constant in bovine placenta and fetal adrenal glands at all gestational stages studied. In contrast, P45017 alpha expression was higher in both the placenta and the fetal adrenal glands during the early stages of pregnancy, but declined markedly in both tissues through the period of midgestation. The expression of P45017 alpha increased markedly in the fetal adrenal glands in late gestation. The levels of 3 beta HSD were extremely low in placental tissues, but were higher in the fetal adrenals, where they were found to be slightly elevated in early and late gestation compared to those in midgestational stages. Immunocytochemical examination of the levels of P45017 alpha and 3 beta HSD in the fetal adrenal glands correlated with the results of Western and Northern analyses. In addition, the morphology and distribution of these two enzymes in the developing bovine fetal adrenal glands indicated that while the early activated gland is functional relative to the ability to secrete steroids, structural and functional organization more typical of mature adrenal glands is not achieved until the time of activation of the fetal adrenals in late gestation.
在整个妊娠期，对牛胎盘和胎儿肾上腺中胆固醇侧链裂解细胞色素P450（P450scc）、17α-羟化酶细胞色素P450（P45017α）和3β-羟类固醇脱氢酶（3βHSD）的表达进行了研究。通过蛋白质免疫印迹法和Northern印迹法分析发现，这些酶在胎盘中的表达水平远低于肾上腺。然而，在所研究的所有妊娠阶段，牛胎盘和胎儿肾上腺中P450scc的水平保持相对恒定。相比之下，P45017α在妊娠早期胎盘和胎儿肾上腺中的表达均较高，但在妊娠中期，这两个组织中的表达均显著下降。在妊娠晚期，胎儿肾上腺中P45017α的表达显著增加。胎盘组织中3βHSD的水平极低，但在胎儿肾上腺中较高，且与妊娠中期相比，在妊娠早期和晚期略有升高。对胎儿肾上腺中P45017α和3βHSD水平的免疫细胞化学检查结果与蛋白质免疫印迹法和Northern印迹法分析结果相关。此外，这两种酶在发育中的牛胎儿肾上腺中的形态和分布表明，虽然早期激活的肾上腺在分泌类固醇的能力方面具有功能，但直到妊娠晚期胎儿肾上腺激活时，才会形成更典型的成熟肾上腺的结构和功能组织。
