Expression of AhR and ARNT mRNA in Cultured Human Endometrial Explants Exposed to TCDD

Endometriosis is a debilitating disease found in 10–15 % of reproductive-age women and is characterized by the presence of endometrial tissue outside of the uterus. The present study char-acterizes the expression of AhR and ARNT mRNA in a human endometrial explant culture model in the absence and presence of TCDD exposure. In a parallel, companion study using this model, TCDD exposure was shown to induce CYP1A1 mRNA, CYP1B1 mRNA, EROD (7-ethoxyresorufin-O-deethylase) activity, and CYP1B1 protein in human endometrial explants. Explants were prepared from specimens obtained at laparoscopy or laparotomy from women undergoing surgery for tubal ligation, endometriosis, or pelvic pain unrelated to endometriosis. These specimens were a subset of the specimens used in the parallel study. The explants were cultured in medium containing 10 nM estradiol (E2) or 1 nM estradiol plus 500 nM progesterone (E2 1 P4) with or without