PHOTOSENSITIZER-INDUCED LIPID-PEROXIDATION IN RETINAL HOMOGENATES UNDER ILLUMINATION

In this study, the effect of photosensitizers on lipid peroxidation in the retina was investigated. Porcine retinal homogenate was exposed to illumination from a fluorescent lamp with or without photosensitizers such as hematoporphyrin, rose bengal, and fluorescein for 60 min. The control, which was exposed to illumination without photosensitizers, did not show a significant increase in lipid peroxidation. However, lipid peroxidation in the homogenates exposed to illumination with photosensitizers increased significantly and in a dose-dependent manner. For concentrations of more than 100-mu-M of all three photosensitizers, lipid peroxidation in the retina homogenates increased to a level approximately 2-3 times higher than that in the sample before illumination, and to a level 10 times higher than that of the control. Alpha-tocopherol inhibited hematoporphyrin-induced lipid peroxidation in a dose-dependent manner, but superoxide dismutase did not show an inhibitory effect.