Abstract: Objective To investigate the effects of polylactic acid-polyglycolic acid-polyethylene (PLGA-PEG) stent on matrix metalloproteinase (MMPs) in rabbits with atherosclerosis. Methods 30 adult healthy rabbits were divided randomly into two groups:control group (n=15)　and PLGA-PEG group (n=15). Right iliac arteries of rabbits of PLGA-PEG group were injured by balloon denuded endothelization. PLGA-PEG stents were implanted in rabbits in PLGA-PEG group. MMP-2,9 and pro MMP-2,9 levels of PLGA-PEG group were determined before implantation,7 and 30 d later by SDS-PAGE zymography. MMP-2,9 and pro MMP-2,9 levels were determined in control groups. Results The concentrations of MMP-2,9 and pro MMP-2 in PLGA-PEG group were much higher than those in control group (11 568±2 219,10 364±1 429,13 649±1 894 INT·mm² vs 6 128±1 562,8 519±2 167,8 413±2 156 INT·mm²,P<0.05). There were no significant differences of pro MMP-9 between two groups (P>0.05). In PLGA-PEG group, the levels of MMP-2,9 and pro MMP-2,9 didn′t elevate significantly 7 d later　(P>0.05). However the MMP-2 and pro MMP-2 concentrations were still higher 30 d after implantation （13 935±2 167，15 628±1 739 INT·mm² vs 11 568±2 219，13 649±1 894 INT·mm²，P<0.01）. Conclusion The serum levels of MMP-2 and pro MMP-2 increase significantly in rabbits with atherosclerosis. The MMP-2 level also increases after implantation.

Key words: gelatinase A, gelatinase B