Figure 3. Effect of aging on selected proapoptotic and prosurvival genes. Real-time PCR analysis of selected genes was performed in young (3 months) and old (15 months) rats. The following genes are presented: Inhibitor of apoptosis (IAP)-1 gene (A), X-linked IAP (XIAP) gene (B); p53 gene (C), Bcl-2 gene (D), Bcl-xl gene (E), tumor necrosis factor (TNF)-α gene (F). Interestingly, IAP-1 and XIAP expression was significantly downregulated in the glaucomatous eyes of old rats, but upregulated in young rats. Data represent mean ± standard error of the mean (SEM); n=8; *p<0.05.