Progestin and antiprogestin interactions with progesterone receptors in human myomas

Abstract Progesterone receptors (PRs) in human fibromyomata (myomas) and normal myometrium were characterized by gel filtration, sucrose gradient sedimentation analysis, isoelectrofocusing and ligand specificity. The PR population in myoma tissues, 1242 ± 505 fmol/mg protein, was 3-fold higher than normal myometrial tissues under similar hormonal milieu. The increased PR concentration in myomas appears to be of potential importance in physiopathology of fibromyoma.