LONG-TERM ORGAN-CULTURE SYSTEM TO STUDY THE EFFECT OF UV-RADIATION ONLENS ENZYMES

Environmental factors such as solar radiation and drug treatment are p otential cataractogenic agents. It is suggested that their damaging ef fects accumulate with age. The purpose of the study was to isolate the effect of one factor (UV-radiation) and find out the mechanism by whi ch UV radiation causes damage to the eye lens. We irradiated bovine le nses 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 cultu re. Enzyme activities were analyzed in lens epithelium after five days of incubation in organ culture. The enzymes analyzed were ATPase, whi ch belongs to the transport mechanism in lens epithelium cells, hexoki nase, the key enzyme of the glycolysis pathway, G6PD, which provides N ADPH to the glutathione system and catalase, which protects the cells from H2O2. Optical damage was observed even for the minimal radiation. The same amount of radiation also affected ATPase and hexokinase acti vities. G6PD and catalase were affected only in lenses which received radiation for 90 min. We can conclude that enzymes involved in the tra nsport mechanism and metabolism are more sensitive to UV-A (365 nm) ra diation than enzymes involved in the defense mechanism against oxidati on.