Intermittent exposure to fluorescent light extends lifespan of human diploid fibroblasts in culture.

Abstract

SHORT exposure (3 or 4 h) to fluorescent light one to three times weekly enhances the proliferation rate of human diploid fibroblasts in culture1. This proliferative response is reversible and is mediated through the culture medium, Dulbecco Vogt's supplemented with 10% foetal bovine serum. Conceivably, this increase in proliferation rate might also influence the lifespan of human diploid fibroblasts which undergo a limited number of population doublings (PDs) in culture2. To evaluate the long term effects of repeated light exposure on lifespan, three lines of human fibroblasts originating from adult skin (HU-274), a mince of whole foetus (HU-278), and foetal lung (WI-38), were assayed in quantitative experiments to determine the lifespan measured as cumulative cell number and total PDs.