Öz
Sex steroid hormones (estrogen and progesterone) are important regulators in lacrimal gland functions with the help of its specific receptors. The deficiency of these hormones causes disease of keratoconjunctivitis sicca (KCS) which is characterized with eye dryness. This study was aimed to show the immunohistochemical localization of the ERα, ERβ and PR in intraorbital and extraorbital lacrimal glands of the rat. Following the routine histological procedure, the Strep-ABC immunohistochemical staining method was performed to the lacrimal gland samples obtained from 8 rats under anesthesia. Changing degrees of ERα, ERβ and PR immunoreactivity were determined in cytoplasm and nucleus of the secretory epithelium, duct epithelium, myoepithelial cells and endothelial cells of the intraorbital and extraorbital gland. It was determined that ERα was found intensely in the nucleus of the all structural components of the two glands, whereas ERβ was found intensely located in the cytoplasm. PR immunoreactivity was shown strongly in the lateral membranes of both gland epithelium and in the myoepithelial cells of the intraorbital glands. Also, positive ERβ immunoreaction was detected in the mast cells around the blood vessels in the intraorbital glands, whereas ERα, ERβ and PR positive stromal cells were detected in the interstitial connective tissue of the extraorbital gland. As a conclusion, changing degrees of ERα, ERβ and PR immunoreactivity found in all structural components of both glands supports the idea that the receptor based estrogen and progesterone hormones have an effect on the maintainance of the structural and functional integrity of the lacrimal gland.