A4: UV RADIATION ON CORNEA & LENS: ANTIOXIDANTS, ENZYME ACTIVITY & GENE EXPRESS

紫外线（UV）射线之间的联系，形成

The association between ultraviolet (UV.) rays, formation of oxygen free radicals, inactivation of antioxidative enzymes and the appearance of photokeratitis and age-related cataract has been established. Since the possible decrease in the stratosphere's ozone layer as well as the large incidence of cataracts in our elderly population, UV induced cataracts has public and environmental health implications. We propose to study tile mechanisms of UV induced corneal and lens damage as well as those mechanisms associated with the protective effect observed with some low molecular weight antioxidants. Specifically, we propose to study the effect of LN radiation on enzymes that catalyze the removal of radical oxygen species; enzymes related to the generation of NADPH and reduced glutathione. The alteration of these enzymatic kinetics will be determined in the presence of varying concentrations of antioxidants such as vitamin C, vitamin E and beta-carotene. In addition, we also propose to look at the level of gene expression and to isolate gene(s) affected by UV irradiation in lens and cornea tissues. The results of the proposed studies may lead to a better understanding of the prevention of LN-induced opacity of the corneas and the lens and could potentially address future research approaches leading to the prevention or delay of cataract formation through nutritional antioxidants.