Immunohistochemical localization of epidermal growth factor in human main and accessory lacrimal glands

Immunohistochemical localization of epidermal growth factor (EGF) in human main and accessory lacrimal glands has been investigated using monoclonal and polyclonal antibodies. Positive stain of EGF was localized in the cytoplasm of the acinar cells and the epithelial cells of the intra- and interlobular ducts of the main lacrimal glands, including both the palpebral and orbital lobes, and of the accessory lacrimal glands (gland of Krause, gland of Wolfring) as well. Meibomian glands showed weak immunoreactivity. Positive stain in the conjunctival epithelium including goblet cells was not observed. These results suggest that the mature form of EGF is produced in both the main and accessory human lacrimal glands and secreted into the tear fluid as a constant and crucial component.