ABSTRACT
Background The sex hormones plays an important role in the incidence of dry eye,especially for the regulation of function.However,the effects of sex hormones on lacrimal gland epithelial cells are below understand.Objective This study was to investgate the effects of estradiol and testosterone on the apoptosis of lacrimal gland cells induced by H2O2.Methods The lacrimal gland tissue was obtained from 2- or 3-month-old clean male New Zealand rabbits and the lacrimal gland epithelial cells were cultured in vitro using esplant culture method.The cells were identified by pan cytokeratin antibodies with immunocytochemistry.lacrimal gland epithelial cells were incubated in the 96 well plate at the density of 5 × l04 cells/ml for 44 hours.Estradiol or testosterone with the concentrations of 1 × 10-5,1 × 10-6,1 × 10-7,1 × 10-8 mol/L were added into the medium for 24 hours respectively and 1× 10-4 mol/L H2O2 treated the cells for 1 hour to induce the apoptosis in experimental groups.The cells treated by only 1 × 10-4 mol/L H2O2 were used as apoptotic control group,and the cells cultured by regular method were used as blank control group.The cell viability in different groups was detected using MTT at 570 nm ( A570 ),and the apoptotic rates of the cells were assayed using Annexin V/PI double staining.This use and maintain of experimental animals followed the Regulation for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The cultured cells showed the irregular polygon in shape,and about 80％ cells was positive response for cytokeratin.MTT assay showed that the lower A570 values were detected in the H2O2-induced group,various concentrations of estradiol or testosterone groups compared with blank control group (P＜0.01 ).The A570 values in 1 × 10-5,1 × 10-6,1 × 10-7 mol/L estradiol groups or 1 × 10-6 mol/L testosterone group were significantly higher than ones of H2 O2-induced group (P＜0.01 ).Compared with corresponding concentrations of testosterone groups,the A570values in various concentrations of estradiol groups were elevated( P＜0.01 ).The apoptosis rates at the early and later phase were significantly declined in both estradiol group and testosterone group in comparison with H2 O2-induced group (P ＜ 0.01,P＜ 0.05 ),and those in estradiol group were lower than the testosterone group( P＜0.01,P＜0.05 ).Conclusions Estradiol and testosterone suppress the apoptosis of lacrimal gland cells induced by H2O2,and the stronger effect is found in estrogen.The inhibition of estrogen on lacrimal gland cell apoptosis show a dose-dependent manner to some extent.