Aim To investigate the effects of different doses of atorvastatin on cardiomyocyte apoptosis and primary mechanisms in acute myocardial infarction(AMI).MethodsTwenty-four New Zealand rabbits were randomly separated into three groups: the control group treated without lipid-lowering drugs,0.5 mg/(kg·d) and 5 mg/(kg·d) atorvastatin groups with 3 days of treatments.Then,the model of AMI was established by coronary-occluded method,and six hours later,cardiomyocyte apoptotic rate and the expression of Bax and Bcl-2 were detected.Results⑴Compared with control and 0.5 mg/(kg·d) atorvastatin groups,the apoptotic rate of infracted and border zone in 5 mg/(kg·d) atorvastatin group significantly lowered(16%±5% vs 23%±7% and 22%±5%,p<0.01;15%±5% vs 26%±6% and 25%±6%,p<0.01;respectively).⑵The content of Bax had no changes in every group(61±9 vs 62±77 and 67±7,p<0.05;57±6 vs 59±10 and 60±8,p<0.05),while that of Bcl-2 was evidently increased in 5 mg/(kg·d) atorvastatin group than the control group and 0.5 mg/(kg·d) atorvastatin group in infracted and border zone(60±9 vs 45±7 and 52±12,p<0.01;61±13 vs 48±9 and 52±11,p<0.05).⑶Correlation analysis indicated that there was a negative correlation between the rate of cardiomyocytes apoptosis and Bcl-2 expression(r=-0.672,p<0.01;r=-0.735,p<0.01),while there were no relation between the apoptotic rate and Bax(r=0.133,P=0.559;r=0.177,P=0.409)by Pearson correlation analysis.ConclusionsEarly intensive atorvastatin intervention may decrease cardiomyocyte apoptosis.Atorvastatin may be through pro-expression of Bcl-2 to resist apoptosis.Early intensive atorvastatin treatment may yield more significant benefits in AMI.