Figure 5. Changes in cellular pro-apoptotic proteins. RGC-5 cells incubated in filtered light for 48 h showed an increased production of pro-apoptotic Bax and cleaved (17 kD) caspase-3 proteins compared with cells grown in the dark (A). Quantification by densitometric analysis of protein levels showed the effect to be significant in both cases (*p<0.05, by one-way ANOVA followed by a post-hoc Bonferroni test; n=4). All extracts were prepared, in these experiments, from cells incubated in the presence of serum (black bars represent cells incubated in the dark and unfilled bars in the light).