Endothelin receptor subtypes in the microvillous trophoblastic membrane of early gestation and term human placentas

in European Journal of Endocrinology

The 125I-labeled endothelin-1 ([125I]ET-1) binding sites in microvillous membranes from early gestation and term human placentas were investigated. The Kds for [125I]ET-1 binding to early gestation (68 +/- 15 pmol/l) and term (45 +/- 8 pmol/l) microvilli (n = 4) were not significantly different. The density of binding sites decreased significantly, from 243 +/- 80 fmol/mg protein in early gestation microvilli to 54 +/- 10 fmol/mg protein in term microvilli. The endothelin (ET) receptor (ET-R) subtype profiles were determined by competition binding studies with unlabeled ET-1, ET-3, and selective agonists and antagonists for ETA-R and ETB-R. In early gestation placental microvilli, we observed the presence of 72%) ETB-R, (mainly ETB2-R subtype), and 28%. ETA-R. Only ETB-R (mainly the ETB2-R subtype) was present in term placental microvilli. We suggest that the ETB-R on the placental microvillous membrane is involved in specific trophoblastic functions and may play a major role in ET clearance by modulating the amounts of ETs in the maternal intervillous blood space.

If the inline PDF is not rendering correctly, you can download the PDF file here.

 

     European Society of Endocrinology

Related Articles

Article Information

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 161 98 0
PDF Downloads 60 42 0

Altmetrics

PubMed

Google Scholar