Figure 5. More pronounced collagen cross-linking process in old mice. (A) Hepatic genes expression of Lox, Loxl2,Tg2 and Adamts2 (Mean ± SEM) (n=6/group). (B) Sirius red stained sections were observed under polarized light microscopy (200x magnification) to evaluate fiber thickness according to their color. The four different colored collagen fibers were quantified by morphometrical analysis (see methods) (n=6/group). Statistical analysis was performed by two-way ANOVA for repeated measures (boxes) followed by Bonferroni’s post-hoc correction. *P<0.05; **P<0.01 for differences between age groups.