Degenerative and age-related changes in the x-irradiated kidney of the rat

Exposure of rat kidney to a single dose of radiation (4000 rad) produced degenerative changes and accumulation of fluorescent granules after a latent period of approximately 8 weeks. The appearance of these fluorescent granules corresponded to the development of structural damage to the kidney. Radiation produced relatively minor changes in the lipid content of the kidney. The level of cholesteryl esters was increased, arachidonic acid content was decreased, and there was a progressive increase in fluorescent substances related to aging, as detected by thin layer chromatography, in chloroform-methanol extracts of the irradiated kidney. However, there was no apparent loss of vitamin E or ubiquinone and no increase in TBA values or diene conjugation as might be expected as effects of lipid oxidation. These changes were evident by the second month following irradiation and corresponded to the development of the morphological changes. The presence of lipofuscin substances, reduced arachidonic acid, and an increase in cholesteryl esters indicated an acceleration of aging in the radiation-exposed kidney. The relationship of lipid oxidation to the acceleration of aging and the production of acute renal lesions was not apparent