The effect of 2-AP on atherosclerosis. Male apoE ^−/− mice at 6 weeks of age were gavage-fed 200 μL water (control) or 200 mg/kg BW of 2-AP once every other day for 24 weeks. Heart-aorta samples were collected. (a) Frozen sections were cut from the mouse aortic sinus and stained with Oil-Red-O. Magnification = 100. (b) The average area (μm²) of the lesions in sections was determined in mice given 2-AP or water as a vehicle control. (c) Aortas from the aortic root to the iliac bifurcation were collected and opened longitudinally. The en face preparations were fixed and stained with Oil-Red-O. Magnification + 0.5x. (d) The atherosclerotic lesion area and the total aortic area were measured. Data are expressed as the percentage of the aortic surface area covered by atherosclerotic lesions, after determining the atherosclerotic lesion area and the total aortic area. Values are the mean ± SEM of 12 mice. * as compared to untreated control mice.