Interacting influences of pregnancy and corneal injury on rabbit lacrimal gland immunoarchitecture and function

PURPOSE. Previous reports indicated that pregnancy and corneal injury (CI) trigger alterations of lacrimal gland (LG) growth factor expression and redistributions of lymphocytes from periductal foci to acini. The purpose of this study was to test our hypothesis that pregnancy would exacerbate the changes induced by CI. METHODS. Corneas were injured with scalpel blades, and, 2 weeks later, LGs were collected for immunocytochemistry and Western blot analysis. Lacrimal fluid was collected tinder basal- and pilocarpine-stimulated conditions for protein determination and Western blot analyses. RESULTS. There were significant increases of immunoreactivity for prolactin, TGF-beta 1, and EGF in duct cells during pregnancy and after CI, most prominent in pregnant animals with CI. Pregnancy decreased baseline lacrimal fluid secretion, whereas CI did not have a noticeable effect; pregnancy and CI combined resulted in increased fluid production. Pregnancy and CI each increased pilocarpine-induced lacrimal fluid production, whereas protein concentrations were decreased. Prolactin, TGF-beta 1, and EGF were detected in LG by Western blot analysis but were minimally detectable in lacrimal fluid. RTLA(+) and CD18(+) cells were redistributed from periductal to interacinar sites during pregnancy and after CI, most prominent in pregnant animals with CI. CONCLUSIONS. Like pregnancy, CI is associated with redistribution of immune cells from periductal to interacinar sites and enhanced immunoreactivity of prolactin, TGF-beta 1, and EGF in ductal cells. Although baseline lacrimal fluid secretion varied, the glands of all three experimental groups produced significant amounts of fluid in response to pilocarpine, but protein concentrations were decreased.