Abstract: AIM To observe the presence and time course of GLP-1R expression after myocardial ischemia/reperfusion (MI/R) injury in rats. METHODS Male Sprague Dawley rats underwent a 30-min transient left coronary artery occlusion followed by reperfusion. Myocardial infarction was confirmed by electrocardioscope and cardiac ultrasound. Immunohistochemical staining and Western blot of GLP-1R were performed to observe GLP-1R expression in rats at different time points. RESULTS Decrease of cardiac ejection fraction was observed by cardiac ultrasound. GLP-1R expression by Western blot analysis reached a peak at the time point after 8 h reperfusion, significantly higher than in the control group (P<0.01) and remained at a high level at day 1 and day 3 compared with those in sham-operated rats (P<0.05, P<0.01). At 1 week after MI/R, GLP-1R expression showed no significant difference compared with that in healthy myocardium. Immunohistochemical staining showed the same trend of GLP-1R expression by Western blot analysis in the myocardial infarcted/ischemic area. CONCLUSION Myocardial ischemia/reperfusion activates the change of GLP-1R expression first by increase and then recovery to normal.