Objective     To identify the effects of adenovirus mediated adenine nucleotide translocase 1 (ANT1) gene transfection on the apoptosis of rat vascular smooth muscle cells (VSMCs).     Methods     After adenovirus-mediated ANT1 (Ad-ANT1 ) or adenovirus (Ad-GFP) infected rat primarily cultured VSMCs

Hoechst 33258 staining for the VSMCs was observed by laser confocal microscopy for cell apoptosis. Flow cytometric analysis was used to detect the proportion of VSMCs apoptosis with Annexin V staining. The expressions of Bcl-2 and Bax were also detected by Western blot analysis.     Results     Laser confocal microscopy showed a progressive increase in the percentage of apoptotic VSMCs after Ad-ANT1 infection [(13.40±1.14)% in Ad-ANT1 group vs (1.80±0.84)% in Ad-GFP group

P0.01]. Flow cytometric analysis indicated a significant increase in the percentage of apoptotic VSMCs after that Ad-ANT1 infection [(10.66±1.75)% in Ad-ANT1 group vs (3.13±0.37)% in Ad-GFP group

P0.05]. The results of Western blotting indicated that the Bax expression was upregulated in VSMCs transfected with adenovirus-mediated ANT1 (Ad-ANT1 ) compared with cells of adenovirus-empty（Ad-GFP）group.  Meanwhile

there is no significant difference in the Bcl-2 expression in two groups.     Conclusion     Overexpression of ANT1 gene may induce apoptosis of rat VSMCs through upregulating Bax expression．