Oral Everolimus Reduces Adventitial Cell Activation and Neointima Formation in Balloon-Injured Rat Carotid Artery

BACKGROUND AND OBJECTIVES: Previous studies suggest that phenotypic conversion, proliferation and migration of adventitial fibroblasts after balloon injury have an important role in neointimal formation and vascular remodeling. The present study evaluated whether orally administered everolimus (a macrolide of the same family as sirolimus) reduces adventitial cell activation and neointimal formation in balloon-injured rat carotid arteries.

MATERIALS AND METHODS: Oral everolimus (1.25 mg/kg/day), or a matching placebo, was administered daily to 30 rats by gavage, starting 3 days before balloon injury. The treatment effects were assessed 3, 7 and 14 days after injury.

RESULTS: The oral everolimus group showed a significant reduction in adventitial cell proliferation at 3 days after injury and significant neointimal formation reduction compared to the control group at 7 and 14 days after injury (control group 0.06±0.01 mm2, everolimus group 0.01±0.01 mm2, p<0.01 and control group 0.28±0.06 mm2, everolimus group 0.08±0.03 mm2, p0.01).

CONCLUSION: Oral everolimus reduces adventitial cell activation and neointima formation in balloon injured rat carotid arteries.