The Development Of A Scopolamine-induced Dry Eye Model In Rabbit And The Exploration Of Its Mechanism

Purpose:Discover how to successfully use scopolamine-induced rabbit dry eye model and study its possible mechanism.Method:Choose 20 New Zealand white rabbits weighting 2.0-2.5kg,divided them into two groups randomly named experimental group and control group.10 rats in each group.continuous subcutaneous scopolamine 0.8ml(SCOP concentration formulated for 5mg / ml),four times a day,respectively,8:00,12:00,16:00,20:00,intervention for 14 days in the experimental group,whereas the control group injected with sterile saline.Respectively,before the intervention,the 3th day,the 7th day,the 10 th day,14 th day,all animals was measured tear secretion and treated with 1% sodium fluorescein drops in rabbit ocular surface,observed under slit lamp,assess corneal epithelial defect case and photographed.After the intervention is finished,all animals euthanized.7 animals in each group were taken cornea and conjunctiva,half of the cornea and the upper half of the bulbar conjunctiva was used to extract the total RNA,analysis of inflammatory cytokines IL-1? Tnf-? and conjunctival epithelium MUC5 AC m RNA expression,the other half of the cornea and below conjunctiva for western-blot analysis of experimental inflammatory cytokines Tnf-? protein levels;three rabbit whole cornea and below conjunctiva for paraffin embedding HE staining,the upper conjunctival packaged with OCT and made frozen sectionsfor immunohistochemistry of conjunctival goblet cells MUC5 AC.Result:Continuous Subcutaneous scopolamine 14 days,the amount of tear secretion decreased significantly(before intervention 16.58 ± 2.22,after the intervention of3.57 ± 1.08,P <0.00),meanwhile sodium fluorescein corneal staining scores increased significantly(before intervention 0.33 ± 0.52,after intervention 8.5 ± 1.05,P <0.00).In the control group no significant difference in the intervention(before intervention 16.8 ± 1.29,after intervention17.0 ± 0.89,P> 0.05).after Intervention14 days Sacrificed all animals and got the corneal and conjunctiva tissue.Realtime PCR display IL-1? ? Tnf-? were significantly upregulated and the difference between two groups was statistically significant(P <0.00).Western-blot results showed Tnf-? protein levels higher than the control group in the cornea and conjunctival tissue.conjunctiva immunofluorescence showed MUC5 AC expression in the experimental group was significantly lower than the control group;HE staining showed the cornea and conjunctiva in the experimental group more inflammatory cell infiltration compared with the control group.Conclusion:Continuous subcutaneous injection of scopolamine 4mg every time,four times a day,sustainning 14 days,can successfully induce a rabbit model of dry eye.This process is consistent with clinical dry eye patients.It can be a good tool for researshing the pathogenesis of dry eye and find new relative drugs in the future.