Conley A J, Rainey W E, Mason J I
Cecil H and Ida Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235-9051.
J Mol Endocrinol. 1994 Apr;12(2):155-65. doi: 10.1677/jme.0.0120155.
This study examined fetal steroidogenic enzyme expression and function during pregnancy in the pig. Northern and Western analyses were performed to detect the cytochrome P450 enzyme 17 alpha-hydroxylase/17-20 lyase (P450c17) and that for cholesterol side-chain cleavage (P450scc), as well as 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) expression in several porcine fetal tissues. The data demonstrate higher steroidogenic enzyme expression in the fetal adrenal glands and testes than in the placenta at all stages of development examined. Although steroidogenic enzyme expression was maintained throughout gestation in both the fetal adrenals and the testes, adrenal P450c17 expression was higher in the early and late stages when compared with the intermediate stages of fetal development. The stimulation of fetal adrenal steroidogenic enzyme expression in the later stage fetuses was accompanied by increased expression of P450c17 in both the fetal testes and placenta. The expression of 3 beta-HSD by porcine fetal testes was low compared with that of the fetal adrenal gland at all stages of development. Adrenal explants and cultured cells secreted cortisol and androstenedione but much lower amounts of corticosterone, dehydroepiandrosterone and aldosterone. Secretion of cortisol and androstenedione by adrenal explants was maintained by ACTH for 5 days of culture but declined in controls. In cultured porcine fetal adrenal cells, ACTH and angiotensin II stimulated the secretion of multiple steroids. Porcine fetal testis explants and cultured cells secreted testosterone, dehydroepiandrosterone and androstenedione, but were only moderately responsive to trophic stimulation by LH. In general, the data suggest that the fetal adrenal glands and the fetal testes have the potential to contribute significantly to the production of steroids during pregnancy in pigs.
本研究检测了猪孕期胎儿类固醇生成酶的表达及功能。采用Northern和Western分析方法检测了几种猪胎儿组织中细胞色素P450酶17α-羟化酶/17-20裂解酶（P450c17）、胆固醇侧链裂解酶（P450scc）以及3β-羟基类固醇脱氢酶（3β-HSD）的表达情况。数据表明，在所检测的发育各阶段，胎儿肾上腺和睾丸中的类固醇生成酶表达均高于胎盘。尽管胎儿肾上腺和睾丸中的类固醇生成酶表达在整个孕期都得以维持，但与胎儿发育的中期阶段相比，肾上腺P450c17在早期和晚期的表达更高。后期胎儿的肾上腺类固醇生成酶表达受到刺激的同时，胎儿睾丸和胎盘的P450c17表达也有所增加。在发育的各个阶段，猪胎儿睾丸中3β-HSD的表达均低于胎儿肾上腺。肾上腺外植体和培养细胞分泌皮质醇和雄烯二酮，但皮质酮、脱氢表雄酮和醛固酮的分泌量要低得多。肾上腺外植体分泌皮质醇和雄烯二酮的功能在促肾上腺皮质激素（ACTH）作用下维持了5天的培养期，但在对照组中有所下降。在培养的猪胎儿肾上腺细胞中，ACTH和血管紧张素II刺激了多种类固醇的分泌。猪胎儿睾丸外植体和培养细胞分泌睾酮、脱氢表雄酮和雄烯二酮，但对促黄体生成素（LH）的营养刺激反应较弱。总体而言，数据表明胎儿肾上腺和胎儿睾丸在猪孕期类固醇生成过程中可能发挥重要作用。
