THE INFLUENCE OF UV RADIATION ON REDUCED GLUTATHIONE CONTENT IN EYE LENSES OF ETHANOL DRINKING MICE

Abstract

The experiment was conducted on adult male mice, body weight of 25-26 g. Animals were bred in constant light 12:12 and fed with standard diet. The animals were segregated into one control and three experimental groups. Each group consisted of 5 specimens, n=5. In the first part of the experiment animals of the experimental groups drunk 5%, 10% and 15% ethanol solutions for 10 days and individual daily doses of ethanol were 48, 84 and 118 mg respectively. After 10 days of the experiment animals were decapitated and the lenses were taken immediately. Next the lenses were put into Petri dish filled with physiological saline and placed under UV lamps. The UV system emitted both UV-A and U-B radiation. The lamps were placed 24 cm above the Petri dishes and the lenses were shielded by WG 295 SCHOTT filters which cut of the waves shorter than 295 nm. The biologically effective irradiances of the UV system measured from a distance of 24 cm was 0.000000112 W/cm2 and 0.0000042 W/cm2 for UV-A and UV-B respectively. The lenses were irradiated for 3 hours. These gave biological effective doses of 0.12 kJ/m2 and 0.45 kJ/m2 for UV-A and UV-B respectively. After the exposure the lenses were homogenized in phosphate buffer containing EDTA (pH=7.4). The reduced glutathione content was estimated with Elman’s method using color reactions of thiol groups with DTNB. The method was adapted to microplate reader. Statistical analysis was performed using MANOVA test followed by Tukey’s test. We have found statistically significant interactions between UV and ethanol influence on GSH content in mice lenses (F=4.059; p=0.01). Control animals exposed to UV radiation had significantly lower GSH content of reduced glutathione in eye lenses (p=0.01). This effect did not occur in lenses of animals drinking ethanol and exposed to UV radiation. This suggest protective effect of methanol against UV induced drop or reduced glutathione in mice lenses. Probably alcohol drinking before the exposure to UV could increase activity of antioxidative system, which diminished UV influence on glutathione content in lenses of tested mice.