Experimental Study On Low Molecular Weight Heparin Therapy For Alkali Burnof The Rat Cornea

Objective: The purpose of this study was to consider the effect of the low molecular weight heparin for alkali burn of the rat cornea, to investigate the mechanism of LMWH in the course of alkali burn of the rat cornea. Integrins are heterodimeric cell surface molecules involved in cell-cell and cell-matrix interactions. We detected the expression of integrin in the rat alkali-burned cornea, to investigate the role of integrin in the pathological of alkali burn of the rat cornea, and provide theoretical basis for effective treatment for cornea alkali burns.Methods: Alkali burn of the rat cornea model was established, Wistar rats were selected for experiment and were devided into two groups at random, whici subconjunctival injection of LMWH in the treatment group and saline in the control group. All groups were observed the corneal opacity, neovascularization and hyphema by slit-lamp microscope at day 1, 3, 7, 14, 30 after corneal alkali burns. Corneal inflammation was evaluated histologically after enucleation, fixation with formaldehyde solution, and staining with hematoxylin and eosin(HE), the contents of polymorphonuclear leukocyte(PMN) in corneas by using computer image analysis system were measured. Corneal ultrastructural morphology was observed by transmission electron microscop (TEM). The localization and expression of integrin αν, β2 subunit and ICAM-1 were determined by immunohistochemical mothod.Result: It was found that corneal opacity was slighter in treatment group than that in control group at day 1, 3, 7,14, 30 after cautery, which there was statistically significant difference between the treatment group and the control group(P<0.05). From the point of neovascularization grade, the rat corneal neovascularization in the treatment group was less than that in the control group at day 7, 14, 30 after alkali burn(P<0.05). According to the histologic inflammation, the contents of PMN in LMWH were lower than those in control group at day 1, 3,7, with statistically significant difference(P<0.05). The expressions of integrins αν,β2 subunit and ICAM-1 in normal rat cornea were restricted in epithelia and endothelial cell, and it increased gradually at 1, 3, 7 day(P<0.05), and subsequently the expressions decreased slowly at 14, 30 d . There was no difference among integrin αν,β2 subunit and ICAM-1. The expression of αν,β2 subunit and ICAM-1 in the LMWH group were less than those in the control group at 1, 3, 7 day(P<0.05).Conclusion: LMWH can effectively reduce the inflammatory reaction (PMN), restrain coreal neovascularization and reduce the corneal opacity . Integrin plays an important part in alkali burn of the rat cornea. LMWH therapy may ameliorate coneal alkali burn by reducing the release of integrin and leucocyte. LMWH therapy for alkali burn is safe and may not lead to hyphema tendency.