Representative SMC phenotype in neointima observed by transmission electron microscopy (×8000). A: Control; B: Probucol; C: HXS; D: Normal (SMC form tunica media). SMCs of contractile phenotype obtained from tunica media of normal tissue have rich myofilament in cytoplasm and few organelles related to biosynthesis. However, SMCs with synthetic phenotype were more frequently seen in control and they have more organelles (→) related to biosynthesis and fewer myofilament in cytoplasm. Both probucol and XS0601 inhibited transition of SMC phenotype from the contractile to the synthetic, especially in HXS where less increased organelles related to biosynthesis were found.