THE EFFECT OF PREECLAMPSIA ON HUMAN PLACENTAL CORTICOTROPIN-RELEASINGHORMONE CONTENT AND PROCESSING

Prior studies have shown that levels of corticotrophin-releasing hormo ne (CRH) in the umbilical cord blood of infants born after pregnancies complicated by pre-eclampsia are significantly higher than fetal plas ma CRH concentrations in uncomplicated pregnancies. In the present stu dy we have measured CRH by radioimmunoassay in the placenta and fetal membranes from 13 pregnancies complicated by pre-eclampsia and compare d them to 24 uncomplicated pregnancies. In addition we have investigat ed the effect of chronic intrauterine fetal stress on the processing o f CRH in the placenta and fetal membranes. Placental CRH peptide conte nt was significantly higher in the pregnancies complicated by pre-ecla mpsia, 12 900 +/- 4230 pg/g tissue, than in the uncomplicated pregnanc ies, 3130 +/- 430 pg/g of tissue (P<0.01). Gel filtration of the homog enates of normal placenta revealed a major peak of CPH immunnoactivity eluting in the same position as synthetic human CPH. A second smaller molecular weight peak of CRH-immunoactivity was also present and in b oth the amnion and the chorion, the CPH eluted in the position of the smaller molecular weight peak. In contrast, the bulk of the CRH immuno activity in the placenta and fetal membranes obtained after pregnancie s complicated by pre-eclampsia eluted in the position of intact synthe tic human CPH. Thus, zn pregnancy complicated by pre-eclampsia, both p lacental CRH release into fetal plasma and CRH peptide content is high er than in uncomplicated pregnancy.