Fetal placental vascular responses to corticotropin-releasing hormone in vitro. Effects of variation in oxygen tension

Abstract

In this study, using the human placenta perfused in vitro with Krebs' bicarbonate solution, we have examined the effects of changes in oxygen tension on the vasoreactivity of fetal placental blood vessels to corticotropin releasing hormone (CRH). Vasodilatory responses to human synthetic CRH were measured during sub-maximal vasoconstriction of the fetal placental circulation with prostaglandin F(2α) (PGF(2α)) (1-100 μM). Decreases in fetal placental arterial perfusion pressure (FAP) were obtained with CRH under conditions of high oxygen or low oxygen tension; ≥450 mmHg and ≤50 mmHg, respectively. Secretion of CRH into the maternal and fetal placental circulations was measured during changes ..