The Effect of Taurine on Corneal Endothelial Damage by Free-radicals

ABSTRACT

PURPOSE: To investigate the protective effect of taurine on the corneal endothelial damage by oxidative stress. METHODS: Rabbit corneas were mounted in the dual-chambered specular microscope and perfused with bicarbonate-Ringer solution(BR) for 1 hour, and endothelial surface was treated with hypoxanthine-xanthine oxidase(HX-XO) for 5 minutes, and perfused with BR for 3 hours in control group, while perfused with 0.5, 1.0, 2.0 mM taurine in BR in test group. Corneal thickness was measured every 15 minutes and corneal swelling rates were calculated by linear regression analysis. Also, corneal permeability was measured using carboxyfluorescein and fluorometer. Using bovine corneal endothelial cells, MTT assay was done. RESULTS: On MTT assay, cytotoxicity of HX-XO group was 47.69% while those treated with 0.5, 1.0, 2.0 mM taurine were 36.22%, 29.73%, 24.90%, respectively(P<0.05). 0.5, 1.0 and 2.0 mM taurine group (12.88, 10.75 and 8.95 um/hr, respectively) reduced the HX-XO-induced corneal swelling rate(20.08 um/hr)(P<0.05). Corneal endothelial permeability(Pac) showed 7.96 x 10(-4) cm/min in corneas perfused with HX-HO. Also, each taurine solutions markedly reduced Pac(7.00+/-0.29 x 10(-4), 6.51+/-0.25 x 10(-4) and 5.37+/-1.41 x 10(-4) cm/min, respectively)(P<0.05). CONCLUSIONS: The results of this study showed that taurine may prevent hydrogen peroxide-induced corneal endothelial damage.