Purpose: The purpose of the present study was to identify the expression of estrogen and progesterone receptor mRNA and of estrogen and progesterone receptor protein in the conjunctiva of healthy women.
Methods: Specimens of conjunctival tissue of 10 premenopausal women (age range, 13-38 years) were obtained during ophthalmic surgery in patients under general anesthesia. Specimens of approximately 4 mm(2) were taken from superior, nasal, or temporal bulbar conjunctiva adjacent to the bulbus and were immediately deep frozen with liquid nitrogen. Four women underwent strabismus surgery, two had phacoemulsification, and four had vitrectomy. Only three women were taking oral contraceptives. The expression of estrogen receptor (ER)-alpha, ERbeta, and progesterone receptor (PR) mRNA was analyzed by RT-PCR. Western blot analysis on nuclear extracts was performed with the anti-ERalpha mouse monoclonal antibody AB-15, the anti-ERbeta mouse monoclonal antibody 6B12, and the anti-PR mouse monoclonal antibody PgR 636.
Results: In two samples, ERalpha, ERbeta, and PR mRNAs were not accessible because of highly degraded RNA. In the remaining eight samples, an appearance rate of 100% was obtained for all three mRNAs. Similarly, an appearance rate of 100% was obtained for ERalpha, ERbeta, and PR protein in nine tissue samples accessible for analysis; one sample could not be analyzed due to a low amount of tissue.
Conclusions: This study confirms the existence of estrogen and progesterone receptors in the human conjunctiva of premenopausal females. Because the proteins of estrogen and progesterone were also found in this study's specimens, the data indicate that the conjunctiva is a target site for sex steroids. Future studies are needed to elucidate the role of these receptors in ocular diseases involving the conjunctiva.