Abstract: Abstract: Objective To investigate the effects of peroxisome proliferator activated receptor gamma (PPARγ) on ma⁃ lignant arrhythmia in myocardial of ischemia/reperfusion(I/R) rats. Methods Twenty-four SD rats were randomly divided into four groups: Sham group, I/R group, rosiglitazone (ROS) group and PPARγ inhibitor GW9662 (GW) group. The myocar⁃ dial I/R injury was induced by ligation of the left anterior descending coronary artery, with ischemia for 30 min and reperfu⁃ sion for 2 h. The whole process limb Ⅱ lead electrocardiogram was applied to observe the frequency of malignant arrhythmia and record the corrected changes of QT(QTc) interval. RT-PCR was used to detect the expression of PPARγ mRNA. Re⁃ sults There were 5 cases of malignant arrhythmia in ROS group, 2 in I/R and 1 in GW group, 0 was found in Sham group. There was a prolongation of the QTc interval in ROS group than the other groups after ischemic stage (P < 0.05). Compared with I/R group and ROS group, the QTc intervals were shorten in ischemia 30 min and reperfusion process in GW group (P< 0.05). Compared with sham group, the expression of PPARγ mRNA was significantly increased in other three groups (P< 0.05). The expression level of PPARγ mRNA was the highest in ROS group. The expression level of PPARγ mRNA was re⁃ duced in GW group compared with that of I/R group and ROS group (P < 0.05). Conclusion Over expression of PPARγ may lead to the occurrence of malignant arrhythmia in myocardial ischemia/reperfusion rats.

Key words: PPAR-γ, Myocardial Ischemia/Reperfusion, Malignant Arrhythmia, Rosiglitazone