Simple rabbit model of vulnerable atherosclerotic plaque.

The present study investigated the appropriate conditions for induction of lesions in the rabbit atherosclerosis model. Four-week-old male Japanese white rabbits (n = 19) were fed the high cholesterol diet (HCD). This group was classified as the early start (ES) group. The animals were divided into three groups: (i) 1% HCD group (n = 8), (ii) 2% HCD group (n = 8), and (iii) normal diet group (control, n = 3). The HCD groups were divided into two subgroups: (a) balloon injury (BI) group (1% HCD, n = 5; 2% HCD, n = 4), and (b) non-BI group (1% HCD, n = 3; 2% HCD, n = 4). Survival period, histological characteristics, area of plaque, and effects of BI and diet cholesterol content were analyzed. Twelve-week-old male Japanese white rabbits (n = 8) were fed the 1% HCD. This group was classified as the late start (LS) group, and underwent BI in the aorta. The histological characteristics and area of plaque were investigated. The plaque satisfied the three requirements of vulnerable plaque: Lipid rich core, accumulation of macrophages, and thin fibrous cap. The plaque area was significantly greater in the ES group compared to the LS group (p = 0.0037). Survival analysis found no statistical correlation with BI or diet cholesterol content. This study indicates that the simplest conditions for inducing the rabbit atherosclerosis model are 1% HCD, non-BI, and early start of HCD. This model is suitable for experiments with new therapeutic devices.