Long-term organ culture system to study the effect of UV-radiation on lens enzymes

Abstract

Environmental factors such as solar radiation and drug treatment are potential cataractogenic agents. It is suggested that their damaging effects accumulate with age. The purpose of the study was to isolate the effect of one factor (UV-radiation) and find out the mechanism by which UV radiation causes damage to the eye lens. We irradiated bovine lenses with UV-A (365 nm) radiation for 50, 75, 90, 100, and 120 min and followed the optical changes of the lenses in a long-term organ culture. Enzyme activities were analyzed in lens epithelium after five days of incubation in organ culture. The enzymes analyzed were ATPase, which belongs to the transport mechanism in lens epithelium cells, hexokinase, the key enzyme of the glycolysis pathway, G6PD, which provides NADPH to the glutathione system and catalase, which protects the cells from H(2)O(2). Optical damage was observed even for the minimal radiation. The same amount of radiation also affected ATPase and hexokinase activities. G6PD and catalase were affected only in lenses which received radiation for 90 min, We can conclude that enzymes involved in the transport mechanism and metabolism are more sensitive to UV-A (365 nm) radiation than enzymes involved in the defense mechanism against oxidation.