RESUMEN
Background The reduced glutathione(GSH) is a water soluble antioxidant in retina and it is an important component of thiol.Diabetes induce the oxidative response of retina.It is very important to detect the content of thiol in retina for the evaluation of its antioxidant role.Objective This study was to investigate the effect of carnosine,aspirin and a combination of carnosine and aspirin eye drops on the change of the thiol contents in the retina of the diabetic rats. Methods Diabetic models were induced in 76 clean male Sprague-Dawley(SD) rats by intraperitoneal injection of streptozotocin(65 mg/kg).The 0.02 mi sodium citrate buffer was injected in 12 control rats.1%camosine eye drops or 0.05%aspirin eye drops were topically administered respectively in carnosine group (19 rats)or aspirin group(19 rats)two times per day for a period of 8 weeks,and the combination of 1%carnosine eye drops and 0.05%aspirin eye drops was used in the combination group at the same way(19 rats).At the end of 8 weeks.The animMs were sacrificed and the eyeballs were enucleated for the detect of thiols in the retina by colorimetry.Results The body weight of SD rats was significantly reduced and the blood glucose level was evidently arose in model group,camosine group and aspirin group in comparison with control group(P＜0.05),but those of combination group compared with control group was insignificantly changed(P＞0.05).The level of thiol in retina was(1 90.35+46.62)ms/gprot in model group,showing a considerable decrease in comparison with control (202.77+53.49 ms/gprot)(P＜0.05).However,the thiol level rose to(378.40±165.06)mg/gprot in camosine group and(351.88±211.62)mg/gprot in aspirin group,showing a statistically significant difference in comparison with control group(P＜0.05).The content of thiol in combination group compared with control group Was insignificant changed(166.972±50.287 mg/gprot us 202.77±53.49 mg/gprot).Curiously the levels in the combination group were not different from the normal control group. Conclusion The carnosine and aspirin eye drops may protect the retina against the oxidative damage caused by diabetes.