Immunohistochemical localization of prostaglandin H synthase in the female reproductive tract and endometriosis

Prostaglandin H synthase, also known as cyclooxygenase, is an essential enzyme in prostaglandin synthesis. Using a monoclonal antibody and immunohistochemical techniques, we studied the localization of this enzyme in the female reproductive tract and in endometriosis. In the uterus, prostaglandin H synthase was primarily localized to endometrial epithelium with surface epithelium containing more immunoreactive prostaglandin H synthase than glandular epithelium. Fallopian tube secretory epithelial cells also contained prostaglandin H synthase while ciliated epithelial cells did not. Cervical epithelium and myometrial cells did not contain prostaglandin H synthase. A higher percentage of glands in endometriosis and adenomyosis, as compared with eutopic endometrium, contained prostaglandin H synthase suggesting that these tissues are also capable of prostaglandin synthesis. These findings may have important physiologic significance in the mechanisms of embryo implantation, in menstruation, and in the pathophysiologic features of endometriosis.