Presence of Corticotropin in Human Placenta: Demonstration ofin VitroSynthesis

Abstract

Immunoassayable (I) and bioassayable (B) ACTH activity is prsent in extracts of extensively washed human placental tissue and dispersed viable trophoblasts (Tr). Similar concentrations (I) (1.7-2.4 ng/g) are present in term placentas from elective cesarean section or vaginal delivery and from placentas obtained by prostaglandin-induced abortion at 12, 15 and 18 wk of gestation. Oral dexamethasone (8-12 mg) administered over an 8-48 h period to delivery does not significantly alter placental ACTH content. B-ACTH concentrations are 31-40% of I-ACTH. Sephadex G-50 filtration of term placental homogenates demonstrates two I-ACTH peaks, 1 eluting in the void volume and the other eluting in the region of synthetic hACTH1-39. When Tr are incubated in tissue culture medium, ACTH content of cells and of medium is significantly greater than pre-incubation levels.