Objective:To explore the effect of xanthine oxidase inhibitor allopurinol on left ventricular remodeling and function in rats with myocardial infarction(MI).Methods:MI models were produced by ligation of anterior descending coronary artery.The survivals were randomly divided into 3 groups:sham operation group

MI group and allopurinol group[50mg/(kg·d)

n=15]. After 28 days

the parameters of echocardiogram and hemodynamics were investigated.The infarct size

LV weight index were detected

too.In addition

the activities of xanthine oxidase(XO) and ·O2-

·OH-scavenging were examined;the expression of XO was detected by Western blot.Results:Compared with sham group

the LV weight index and expression of XO were increased;the activity of XO was boosted but the heart function and activities of ·O2-

·OH-scavenging were decreased(P<0.01).Compared with MI group

the LV weight index were decreased;the activity of XO was depressed but the heart function and activities of ·O2-

·OH-scavenging were increased(P<0.05 or P<0.01).There were no significant difference in heart rate

arterial blood pressure

infarct size and XO expression between allopurinol and MI group.Conclusion:Allopurinol could improve LV remodeling and function in rats with MI.The protective mechanism could be related to its ability to depress the activity of XO and reduce reactive oxygen species.