OBJECTIVETo study the effect of Xiongshao Capsule (XSC) on vascular remodeling in experimental atherosclerotic (AS) rabbits, and to explore the possible mechanisms.

METHODSRabbit's fractional AS model was established by denuding and injuring the abdominal artery with 4F.Fogarty catheter, and followed with high cholesterol feeding. The animals were randomly divided into 8 groups, namely, the modeled group of 3 days, 2 weeks and 6 weeks after balloon injury (A, B and C); the single endothelium injury group (D), the probucol treating group (E), the low-dose and high-dose XSC treating group (F and G) and the normal control group (N). Except the rabbits in Group N and D, the other groups were all fed with high fat forage. Histopathological examination of abdominal aorta with the most obvious lesion was performed, and the changes of related vascular remodeling indexes after arterial injury were observed using computerized image analyzing system; the correlation analysis between progress of intimal proliferation and vascular remodeling were performed as well.

RESULTSArtery intimal proliferation progressed gradually as time went on, which was more significant in Group C as compared with that in Group B and D (P < 0.01). All the drugs could reduce the maximum intima thickness (MIT). Moreover, both high-dose XSC and Probucol profoundly decreased the intima area (IA), showing significant difference as compared with that in Group C (P < 0.01). The internal elastic laminal area (IELa), external elastic laminal area (EELa), minimum lumen diameter (MLD) and lumen area (LA) in Group A increased significantly, as compared with that in Group N (P < 0.01). At 6 weeks after balloon injury, with the further intimal thickening, IELa, EELa reduced contrarily, resulting in insufficient vascular compensation, lumen stricture and MLD reduction (P < 0.01). Improvement of MLD and LA was shown in all the drug treated groups, with significant difference in comparing with those in Group C (P < 0.01).

CONCLUSIONSingle endothelium injury may be one of the initiating elements of pathological vascular remodeling, which could be intensified by hyperlipemia. Intimal proliferation and vascular remodeling jointly participated in the pathological course of AS lumen stricture after endothelium injury. XSC plays its action in preventing and treating AS through inhibiting intimal proliferation after balloon injury and intervening pathological vascular remodeling.