Pre-eclampsia and gestational age differently alter binding of endothelin-1 to placental and trophoblast membrane preparations.
The aim of the study was to compare the binding of endothelin-1 (ET-1) to membranes from placental tissue and trophoblast cells in normal and pre-eclamptic pregnancies. Plasma membranes from placental tissue and trophoblastic cells were prepared from 15 control and 18 pre-eclamptic pregnancies at either preterm (weeks 31-36) or term (weeks 37-40). ET-1 binding to tissue membranes was measured by a radioreceptor assay. In addition, binding of 56 nmol/l [125I]ET-1 to plasma membranes of trophoblastic cells was determined. In pre-eclampsia, placental membranes bound less (P < 0.01) ET-1 owing to fewer (P < 0.01) receptors at preterm than in the corresponding preterm controls. In contrast, binding of [125I]ET-1 to plasma membranes of trophoblast cells was higher (P < 0.01) in pre-eclampsia at both gestational stages than in the controls. Incubation of trophoblast cells with hydralazine reduced binding by 70%. We conclude that pre-eclampsia is associated with changes in the binding of ET-1 to its placental receptors. Moreover, the data suggest that pre-eclampsia affects non-trophoblast cells in the opposite manner to the trophoblast.
Cervar
M
M
Department of Obstetrics and Gynecology, Karl-Franzens-University of Graz, Austria.
Kainer
F
F
Desoye
G
G
D000328:Adult; D002462:Cell Membrane / Q000378:metabolism; D016232:Endothelins / Q000378:metabolism*; D005260:Female; D006801:Humans; D006830:Hydralazine / Q000494:pharmacology; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D017466:Receptors, Endothelin / Q000378:metabolism; D013997:Time Factors; D014327:Trophoblasts / Q000378:metabolism*
D016232:Endothelins; D017466:Receptors, Endothelin; D006830:Hydralazine