Immunohistochemical localisation of cyclooxygenase in the human uterus

The distribution in the human uterus of the enzyme cyclooxygenase,, involved in prostaglandin synthesis, was studied using the peroxidase-antiperoxidase immunohistochemical technique. Specific staining was observe only during the luteal phase of the menstrual cycle It was found that cyclooxygenase was localised in the surface and glandular epithelium of the endometrium but could not be demonstrated in the endometrial stroma, myometrium or blood vessels The location of specific staining for cyclooxygenase and its variation during the menstrual cycle was the same regardless of the amount of menstrual blood loss. Tissue samples obtained from early pregnant and postmenopausal patients failed to exhibit any specific staining.