Neointimal Formation After Balloon-Induced Vascular Injury in Yucatan Minipigs is Reduced by Oral Rapamycin

Abstract

Rapamycin, a macrolide antibiotic known to prevent allograft rejection, is a potent inhibitor of cell proliferation. Therefore we studied the effects of orally administered rapamycin in a pig model of balloon injury in an attempt to reduce the cellular proliferation and neointimal formation thought to play a role in restenosis. Twenty Yucatan minipigs, divided into groups of 10 animals each, were subjected to balloon inflation of the carotid arteries. One group received the methylcellulose vehicle for rapamycin, whereas the second group was treated for a total of 31 days with 2.0 mg/kg of rapamycin administered daily by oral gavage. This dose and treatment regimen produced significant (p