The effect of pre-eclampsia on human placental corticotrophin-releasing hormone content and processing

Abstract

Prior studies have shown that levels of corticotrophin-releasing hormone (CRH) in the umbilical cord blood of infants born after pregnancies complicated by preeclampsia are significantly higher than fetal plasma CRH concentrations in uncomplicated pregnancies. In the present study we have measured CRH by radioimmunoassay in the placenta and fetal membranes from 13 pregnancies complicated by pre-eclampsia and compared them to 24 uncomplicated pregnancies. In addition we have investigated the effect of chronic intrauterine fetal stress on the processing of CRH in the placenta and fetal membranes. Placental CRH peptide content was significantly higher in the pregnancies complicated by pre-eclampsia, 12 900 ± 4230 pg/g tissue, than in the uncomplicated pregnancies, 3130 ± 430 pg/g of tissue ( P<0.01). Gel filtration of the homogenates of normal placenta revealed a major peak of CRH immunoactivity eluting in the same position as synthetic human CRH A second smaller molecular weight peak of CRH-immunoactivity was also present and in both the amnion and the chorion, the CRH eluted in the position of the smaller molecular weight peak. In contrast, the bulk of the CRH immunoactivity in the placenta and fetal membranes obtained after pregnancies complicated by preeclampsia eluted in the position of intact synthetic human CRH Thus, in pregnancy complicated by pre-eclampsia, both placental CRH release into fetal plasma and CRH peptide content is higher than in uncomplicated pregnancy.