Abstract: Objective To investigate the effect of atorvastatin on the collateral vessel growth in hypercholesterolemia rats.　Methods　Twenty-eight adult SD rats were given a high-fat diet for 8 weeks, to establish a model of collateral vessel growth induced by ligature of femoral artery in hypercholesterolemia rats hind limb. Rats were randomly divided into a ligation-only group (L group), a hypercholesterolemia + ligation group (HL group), and an atorvastatin (0.3mg/kg/2w, intraperitoneal injection) + hypercholesterolemia + ligation group (AL group). After a 7-day survival, the effects of atorvastatin on collateral vessel growth and the change of the expression pattern of important cytokines were detected by angiography, HE staining, and confocal immunofluorescence.　Results　Compared with the L group, the number of collateral vessels in the HL group reduced, and the collateral vessels growth was impaired, showing that the intimal hyperplasia was manifested and the tunica media was significantly thickened, resulting in narrowing of the vascular lumen, and cell proliferation of the vascular wall and decreasing of the adventitia inflammatory cells. Compared with the HL group, after the application of atorvastatin in the AL group, the growth of collateral vessels significantly improved, and developed into collateral vessels with a larger lumen. The cell proliferation of vascular wall, the adventitia inflammatory cells, and the number of visible collateral vessels all increased. There were statistical significance among the number of collateral vessels, cross sectional area of collateral vessels and the immunofluorescence intensity difference (P<0.05).  Conclusions　Hypercholestero- lemia impairs the growth of collateral vessels in the rat hind limbs. Atorvastatin can improve the proliferation of vascular wall cells and the increasing of adventitia macrophage cells, resulting in promoting and restoring the growth of collateral vessels.

Key words: Hypercholesterolemia, 　Atorvastatin, 　Ischemia disease;　Collateral vessel