Atherosclerotic lesions in the aortic sinus. (a and b) Representative photographs of Sudan III–stained aortic root sections from apoE-KO and apoE-KO/eNOS-Tg mice fed on a high-cholesterol diet for 8 weeks. Sections were taken at the same level of aortic valves (original magnification ×15). (c) Quantitative analysis of atherosclerotic lesion size in males and females of apoE-KO and apoE-KO/eNOS-Tg mice. Total lesion area of five sections in the aortic root from each mouse was quantified morphometrically as described in Methods. Each symbol represents the lesion area measurement from an individual mouse, with the mean per group indicated by a horizontal line. After 8 weeks on a high-cholesterol diet, the atherosclerotic lesion areas were significantly increased in apoE-KO/eNOS-Tg compared with apoE-KO mice. *P < 0.001 vs. male apoE-KO mice; **P < 0.01 vs. female apoE-KO mice.