Aim To investigate the effects of advanced glycation end product(AGE)on cellular proliferation and expression of plasminogen activator inhibitor-1(PAI-1)in cultured rat aortic vascular smooth muscle cell(VSMC).Methods Primary cultures of smooth muscle cell from rat aorta were exposed to AGE of different times and different concentrations.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)assay was adopted for the quantification of the cell proliferation ratio and PAI-1 expression was determined by reverse-transcription polymerase chain reaction(RT-PCR).Results Cell proliferation in different AGE concentration medium was greater than that in nonglycated BSA medium(p<0.05),except for 8 hours.After intervention of AGE,plasminogen activator inhibitor-1 mRNA was increased markedly(p<0.001)in a time-related manner.The expression of plasminogen activator inhibitor-1 mRNA was upregulated in a dose-related manner(0.85±0.05,0.97±0.05,1.08±0.12,1.41±0.05),in comparison with that in control group(0.80±0.03,p<0.05).Conclusion AGE induced proliferation and the expression of PAI-1 mRNA in VSMC.This may be involved in the pathogenesis of atherosclerosis in patients with diabetes mellitus.