Murphy V E, Clifton V L
Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, New South Wales 2310, Australia.
Placenta. 2003 Aug;24(7):739-44. doi: 10.1016/s0143-4004(03)00103-6.
11beta-hydroxysteroid dehydrogenase type 1 and type 2 may be important in the process of human parturition and the regulation of fetal growth, by the modulation of cortisol concentrations in the fetal compartment. Changes in the expression and activity of these enzymes in late gestation have not been well described. This study has examined the gene expression of placental 11beta-HSD1 and 2, activity of 11beta-HSD2 and fetal cortisol concentrations during the final few weeks of human pregnancy and with the onset of labour. Placental 11beta-HSD2 activity decreased significantly between 38 and 40 weeks. There were no significant changes in mRNA abundance or protein expression with gestational age or labour. Placental 11beta-HSD1 mRNA abundance significantly increased with spontaneous labour. Fetal cortisol concentrations increased significantly with spontaneous labour. This study is the first to describe a decrease in 11beta-HSD2 activity in the last few weeks of human gestation. This decrease in type 2 activity, along with an increase in 11beta-HSD1 gene expression may be a mechanism by which cortisol concentrations rise at term to regulate fetal maturation and activate pathways associated with labour.
11β-羟类固醇脱氢酶1型和2型可能通过调节胎儿体内皮质醇浓度，在人类分娩过程和胎儿生长调节中发挥重要作用。妊娠晚期这些酶的表达和活性变化尚未得到充分描述。本研究检测了人类妊娠最后几周及分娩开始时胎盘11β-HSD1和2的基因表达、11β-HSD2的活性以及胎儿皮质醇浓度。胎盘11β-HSD2活性在38至40周之间显著下降。mRNA丰度或蛋白质表达随孕周或分娩无显著变化。胎盘11β-HSD1 mRNA丰度随自然分娩显著增加。胎儿皮质醇浓度随自然分娩显著增加。本研究首次描述了人类妊娠最后几周11β-HSD2活性的下降。2型活性的这种下降，以及11β-HSD1基因表达的增加，可能是足月时皮质醇浓度升高以调节胎儿成熟并激活与分娩相关途径的一种机制。
