Release of bioactive ACTH by perifused human placenta at early and late gestation

This study assessed whether bioactive ACTH is released by the human placenta during perifusion in vitro at early and late gestation. Human placental villous fragments from early (8-12 weeks) and late (38-40 weeks) gestation were perifused at a constant rate for 6-5 h. To assess ACTH-like bioactivity released by this tissue, the perifusion effluent was redirected through adjacent chambers containing freshly dispersed adrenocortical cells obtained from adult rats. Baseline secretion of corticosterone by these adrenocortical cells averaged 95 +/- 26 (S.E.M.) fmol/min, and this increased at least five fold (P