Perkins A V, Wolfe C D, Eben F, Soothill P, Linton E A
Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Headington, Oxford, UK.
J Endocrinol. 1995 Sep;146(3):395-401. doi: 10.1677/joe.0.1460395.
During pregnancy maternal plasma corticotrophin-releasing hormone (CRH) levels rise 1000-fold whilst fetal plasma levels are often 100-fold higher than the concentrations seen in normal non-pregnant human plasma. Despite these high CRH levels neither the maternal nor fetal pituitary releases excessive amounts of ACTH. A specific CRH-binding protein (CRHBP) exists in the maternal circulation which is able to bind and inactivate the ACTH releasing activity of CRH. In this study we have used a specific CRHBP radioimmunoassay to determine the level of CRHBP in fetal and maternal plasma samples. Fetal samples were collected by cordocentesis between 20 and 33 weeks gestation and matched maternal samples were taken by venepuncture at the same time. In a second study, plasma samples were collected from 8 women at fortnightly intervals from week 20 to term, at labour and post-partum. A fetal sample, taken from the umbilical vein, was collected immediately post-delivery. The mean maternal CRHBP concentration for the samples collected between 20 and 33 weeks (n = 23) was 8.12 nmol/l and the fetal level was 8.62 nmol/l. Data from the second study showed that at term the maternal CRHBP concentration decreased significantly (P < 0.025) to 6.32 nmol/l. The fetal CRHBP level also decreased significantly (P < 0.001) at term to a level of 5.84 nmol/l. The CRHBP in both fetal and maternal plasma was shown to be functional by 125I-CRH binding and gel permeation chromatography. The capacity of maternal and fetal plasma to bind 125I-CRH decreased at term in agreement with the quantitation of plasma CRHBP by radioimmunoassay.
在怀孕期间，母体血浆促肾上腺皮质激素释放激素（CRH）水平升高1000倍，而胎儿血浆水平通常比正常未怀孕人体血浆中的浓度高100倍。尽管CRH水平很高，但母体和胎儿的垂体都不会释放过量的促肾上腺皮质激素（ACTH）。母体循环中存在一种特异性CRH结合蛋白（CRHBP），它能够结合并使CRH的促肾上腺皮质激素释放活性失活。在本研究中，我们使用特异性CRHBP放射免疫分析法来测定胎儿和母体血浆样本中CRHBP的水平。在妊娠20至33周期间通过脐静脉穿刺采集胎儿样本，同时通过静脉穿刺采集匹配的母体样本。在第二项研究中，从20周直至足月、分娩时和产后，每两周对8名女性采集血浆样本。分娩后立即从脐静脉采集胎儿样本。在20至33周期间采集的样本（n = 23）中，母体CRHBP的平均浓度为8.12 nmol/l，胎儿水平为8.62 nmol/l。第二项研究的数据显示，足月时母体CRHBP浓度显著下降（P < 0.025）至6.32 nmol/l。足月时胎儿CRHBP水平也显著下降（P < 0.001）至5.84 nmol/l。通过125I-CRH结合和凝胶渗透色谱法显示，胎儿和母体血浆中的CRHBP均具有功能。足月时，母体和胎儿血浆结合125I-CRH的能力下降，这与通过放射免疫分析法对血浆CRHBP的定量结果一致。
