Accumulation of autofluorescent yellow lipofuscin in rat tissues estimated by sodium dodecylsulfate extraction.

Autofluorescent yellow lipofuscin accumulated in the older Wistar rat brain, kidney, spleen and testis was successfully extracted by use of 0.5% sodium dodecylsulfate (SDS)/0.05 M phosphate buffered saline (pH 7.4). The extracts contained three fluorophores, one of which corresponded to yellow lipofuscin and showed an excitation maximum at 400 nm and an emission maximum at 620 nm. The SDS extraction method was found suitable for the accurate quantification of lipofuscin in rat tissues. Lipofuscin thus determined accumulated in brain, kidney, spleen and testis with the increase of age of rats. It was found that kidney was the most susceptible tissue in lipofuscin accumulation, and accumulation in male rat kidney was much higher than that in female rat kidney. Accumulation of lipofuscin in rat tissues was slightly dependent on the lipid peroxidation state of the tissues and the dietary conditions: a vitamin E-adequate, vitamin E-deficient, vitamin E-excessive and oil-rich diet, except that the accumulation in male and female rat kidney was significantly enhanced when fed a vitamin E-deficient diet for 7-10 weeks.