LIPOFUSCIN IS A PHOTOINDUCIBLE FREE-RADICAL GENERATOR

Despite the association between high concentrations of the age pigment lipofuscin and various age-related pathologies, there is contention a s to whether or not the intracellular accumulation of such granules ha s an adverse effect on cell function. In this paper, we present eviden ce to indicate that iipofuscin is a photoinducible free radical genera tor. White light irradiation of lipofuscin granules resulted in the pr oduction of superoxide anions, their rate of production increasing wit h increased light intensity. This effect appeared to be maximal in the blue light region of the spectrum. We speculate that lipofuscin could be detrimental to bodily functions through free radical generation in itiated either by light or interaction with endogenous free radicals.