A comparative in vivo study of the effects of ionizing radiation (accelerated protons) and visible light (400-700 nm) on the retina and retinal pigment epithelium (RPE) of the mouse eye was carried out. Using the methods of fluorescence spectroscopy and high-performance liquid chromatography (HPLC), we analyzed the relative composition of retinoids in chloroform extracts obtained from the retinas and RPEs immediately after exposure of animals to various types of radiation and 4.5 months after they were exposed and maintained under standard conditions throughout the period. The fluorescent properties of chloroform extracts were shown to change upon exposure to various types of radiation. This fact indicates the accumulation of retinoid oxidation and degradation products in the retina and RPE. The data from fluorescence and HPLC analyses of retinoids indicate that when exposed to ionizing radiation, retinoid oxidation processes similar to photooxidation occur. Both ionizing radiation and high-intensity visible light have been shown to be characterized by long-term effects. The action of any type of radiation is assumed to activate the mechanism of enhanced reactive oxygen species production, resulting in a long-term damaging effect.
Keywords: HPLC; eye; fluorescence analysis; ionizing radiation; retina; retinal pigment epithelium; retinoid fluorophores; visible light.