Fig. 2

Lipofuscin levels in CPECs increase in rabbits exposed to cholesterol for longer periods. Representative images of lipofuscin in the LV CPECs from a 0 and b 16 weeks of a cholesterol diet (dHC) and c 32-week-old WHHL rabbits. White signals within the cytoplasm of CPECs are lipofuscin. White pixels over a threshold were measured and plotted in d. Bar graphs at the left of the dashed line denote Japanese White rabbits, whereas the bar at the right denotes WHHL rabbits. The number of rabbits used in this analysis is 0 chol (n = 3), dHC (n = 5) and WHHL (n = 7) for CPEC without foam cells (black bars) and 0 chol (n.a.), dHC (n = 2) and WHHL (n = 5) for CPEC with foam (white bars). Data are the mean ± standard deviation (arbitrary unit, AU), *p < 0.05, **p < 0.01 and ***p < 0.001. Scale bar = 20 μm