Background MG53 preconditioning has been proven to protect the hearts against ischemia/reperfusion (I/R) injury, manifested mainly by reduced myocardial specific biomarker, and decreased infarct size. This study is to observe the effects of MG53 preconditioning on ischemia/reperfusion-induced arrhythmias in the Langendorff perfused rat hearts.

Methods 24 healthy adult SD rats,were randomly divided into Sham group (group S), I/R group (group I/R), MG53 preconditioning group (group M), 8 in each group. In vitro heart was perfused for 20 min before the left coronary artery was occluded 30 min followed by 30 min reperfusion. Compared ECG, LDH of perfused fluid, myocardial infarct size was measured with TTC staining and expression of Caspase3 was measured with Western blot.

Results Dring reperfusion period, compared with group I/R, the LDH in group M reduced significantly, group M had no ventricular fibrillation (VF), greatly decreased the times of ventricular premateure beat (VPB), shorten the duration of ventricular tachycardia (VT), reduced the incidence of ventricular tachycardia and the arrhythmia score. Myocardial infract size and expression level of Caspase had no significant change in two groups.

Conclusions MG53 preconditioning paly a protection role on ischemia/reperfusion-induced arrhythmias in the isolated rat hearts.