Evidence for a stereospecific [³H]etorphine binding in human placenta

Abstract

Placental tissue is a source of receptors for some yolypeptidic 19orn9ones including insulin [B ] an9d somatomedin [CT]_ Hn addition it produces some chorionic, pituitary-like hormones, such as gonadotroph9 [3], somatomammo?ropin 141 , corticotropin ES]_ A recent report [6] indicates that human full term placenta rontzins 61-lipotropin and f&endorplnin. j3-Endorpbin is a polypeptide with morphine-like properties that exhibits a high affinity for opiate receptors in brain and peripheral tissues JT-(PI. Evidence will be presented here Pbat hw9an placenta contains substantial amo9mts of stereospecific binding sites for [%]etorphine, a potent opiate agonist.