Endothelin-1 stimulates proliferation of first trimester trophoblasts via the A- and B-type receptor and invasion via the B-type receptor

Endothelin-1 (ET-1) stimulates proliferation and invasion of first trimester human trophoblast cells. Objective: To test the hypothesis that ET-1 effects are mediated by different receptor subtypes (ETRs: ETR-A, ETR-B). Methods: The location of ETRs in trophoblast cell columns (weeks 6–12) was investigated by immunohistochemistry and autoradiography. Trophoblasts were isolated from first trimester human placentas and proliferative and invasive subpopulations separated using an integrin α6 antibody. Cells were incubated for 24h with 10µM ET-1 and different ETR-antagonists: PD142893 (unselective), BQ-610 (ETR-A) a…