Effects of Liraglutide on Angiogenesis and Myocardium Protection in Acute Myocardial Infarction Rats With its Mechanisms / 中国循环杂志

ABSTRACT

Objective: To observe the effects of liraglutide on angiogenesis and myocardium protection in acute myocardial infarction (AMI) rats with its mechanisms. Methods: Rat's AMI model was established by left anterior descending of coronary ligation. AMI rats were randomly divided into 3 groups Control group, the rats received subcutaneous injection of normal saline, Low dose (LS) group and High dose (HS) group, rats received subcutaneous injection of liraglutide 70μg/(kg?d) and 140μg/(kg?d) respectively; in addition, Sham operation group, rats received normal saline. n=6 in each group, all animals were treated for 2 weeks. 4 weeks later, cardiac structure and function were assessed by echocardiography, morphological changes of myocardium were observed by HE staining, collagen volume fraction (CVF) was calculated by Masson staining, myocardial microvessel density (MVD) and protein expression of vascular endothelial growth factor (VEGF) in marginal zone of infracted region were detected by immunohistochemistry, VEGF protein level was examined by Western blot analysis. Results: Compared with Sham operation group, Control group showed decreased LVEF, LVFS and increased LVEDd, LVESd, CVF, all P<0.01; while MVD and VEGF protein level were similar between 2 groups, P>0.05. Compared with Control group, LS group and HS group had obviously increased LVEF, LVFS, P<0.01 and decreased LVEDd, LVESd, P<0.05, obviously decreased CVF, P<0.01; obviously elevated MVD and VEGF protein level, P<0.01. Compared with LS group, HS group presented obviously increased LVEF, LVFS, P<0.01 and decreased LVEDd, LVESd, CVF, P<0.05; elevated MVD and VEGF protein level, P<0.01 or P<0.05. Conclusion: Liraglutide could improve angiogenesis in AMI rats which might be related to increased VEGF expression and reduced collagen deposition; therefore improve left ventricular systolic function for cardiac protection. The effect had certain relationship to liraglutide dosage.