Abstract

To investigate the effect of liraglutide on myocardial injury in acute myocardial infarction rats by regulating phosphoinositide 3 kinase/protein kinase B signaling. Sprague-Dawley rats were randomly divided into sham group, model group, liraglutide group (0.6 mg/kg liraglutide), LY294002 (phosphoinositide 3 kinase inhibitor) (1.5 mg/kg LY294002) and liraglutide+LY294002 (LY294002 after liraglutide), with 12 rats in each group. Except for the sham group, the acute myocardial infarction rat model was constructed by coronary artery ligation. After successful mold making, the drug group was treated according to the administration method of each group, and the group was injected with equal amount of normal saline intraperitoneally for 2 w. Cardiac function was measured by echocardiography, hemodynamics were recorded by polygraph, myocardial histopathological changes were detected by hematoxylin and eosin staining, the degree of fibrosis was observed by Masson staining, and the expression of autophagy-related factors and proteins related to phosphoinositide 3 kinase/protein kinase B signaling pathway was detected in rats by Western blot. As compared to the sham group, a significant decrease in cardiac function, the degree of myocardial tissue damage and the degree of fibrosis, the expression of autophagy-related proteins and phosphoinositide 3 kinase/protein kinase B pathway-related proteins was significantly decreased; compared to the model group, the cardiac function, degree of fibrosis in liraglutide rats, the expression of autophagy-related proteins and phosphoinositide 3 kinase/protein kinase B pathway-related proteins was significantly increased; in contrast to the liraglutide group, cardiac function was significantly reduced in the liraglutide+LY2940002 group, the degree of myocardial tissue damage and the degree of fibrosis, the expression of autophagy-related proteins and phosphoinositide 3 kinase/protein kinase B pathway-related proteins was significantly decreased; compared with the LY2940002 group, the extent of cardiac function, myocardial tissue damage and fibrosis were alleviated in liraglutide+LY2940002 group rats, the expression of autophagy-related proteins and phosphoinositide 3 kinase/protein kinase B pathway-related proteins was significantly increased. Liraglutide can improve the myocardial injury and protect the cardiac function by activating the phosphoinositide 3 kinase/protein kinase B signal pathway in acute myocardial infarction rats.