Figure 5.

Oil Red-O stains of aortic sinuses from typical L^−/−/A^−/− mouse at various ages. (a) 12 weeks of age. Small, dense, fat droplets are observed near the lumen of the sinus (green arrowheads) with minor accumulation in the media (orange arrowheads). (b) 18 weeks of age: dense lipid droplets are now seen associated with the cellular cap (yellow arrowheads) and at the base of a smaller developing plaque adjacent to the base of the valve (purple arrowhead). Light, patchy droplets are also accumulated below the cap into the focally acellular core (red arrowhead). (c) 24 weeks of age. Lipid in the cap region (yellow arrowheads), along with diffuse fat droplets (red arrowheads) and cholesterol clefts (black arrowhead) within the core. (d) 48 weeks of age. Diffuse lipid in the core and cap. (e) 60 weeks of age. The expansive lesion consists of a more complex core with diminished presence of lipid. Several areas within the core appear lipid-free (white arrowhead) but some dense accumulation is observed within the media of the thin stretched wall (black arrowhead). (f) 72 weeks of age. A more extensive cholesterol cleft formation is seen within the complex lesion extending from the base of the core to the thinned cap (white arrowhead). Multiple lipid-containing foci are observed in the subcapsular region (green arrowheads) and a large calcified region extends from the arterial wall into the core (yellow arrowhead). The surrounding plaque contains patchy, moderately sized fat droplets. Original magnification, 100X.