Light exposure induces antioxidant enzyme activities in eye tissues of frogs

Retina and pigment epithelium of eyes are prone to increased production of reactive oxygen species and are susceptible to oxidative damage. We studied antioxidant enzyme activities in eye tissues exposed to prolonged low intensity (2000 lx) and short-term high intensity light (50000 lx) of visible range. Both prolonged low intensity and short-term intensive light increased superoxide dismutase, glutathione peroxidase and catalase activities in the pigment epithelium of frogs' eyes, while the activity of these enzymes in the retina remained unchanged. Our results suggest that visible light may increase oxidative stress and cause compensatory up-regulation of antioxidant enzyme activities in frogs' eyes.