OA-induced foam cell formation is CD36-dependent. (A) Cellular lipid accumulation in rat aortic SMCs after incubation for 48 hours with vehicle (control), OA (250 μmol/L), or OA (250 μmol/L) plus SSO (250 μmol/L). Magnification ×400. Triglyceride (B) and cholesterol ester (C) levels normalized to cellular protein content in rat aortic SMCs. (D) CD36 was determined by western blotting using a specific antibody. Equal protein loading was confirmed using β-actin antibody. The graph below the blot shows quantification. (E) CD36 was determined by RT-PCR. Equal RNA loading was confirmed using β-actin primers. The graph below the blot shows quantification. Data are expressed as mean ± SEM. ** p < 0.01 compared with the control group, ## p < 0.01 compared with the cells treated with OA alone. OA, oleic acid; SMCs, smooth muscle cells; SSO, sulfosuccinimidyl oleate.