Effect of hepatocyte growth factor on left ventricular remodeling after acute myocardial infarction in canine

Background and objectives To investigate the effect of hepatocyte growth factor (HGF) on left ventricular (LV) remodeling after acute myocardial infarction (AMI). Methods AMI was produced by ligation of proximal left anterior descending coronary artery (LAD) in 12 mongrel canines. These animals were randomized into 2 groups. In HGF group (n=6), canines were injected with pc-DNA3-HGF 1ml (about 300ug) at the margin of infarcted myocardium; in control group (n=6) canines were injected with equal volume of normal saline. Cardiac function and left ventricular remodeling were evaluated with echocardiography at 1, 4, 8 weeks after MI. LV myocardium specimens were obtained at 8 weeks and stained with hematoxylin and eosin for histological examination or with sirius red to assess the collagen content. Results Compared with control group, LVEF in HGF group was significantly higher at 4 weeks (49.61 + 6.66 vs 39.84+6.39; P<0.05) and at 8 weeks (51.57+8.53 vs 40.61+7.67; P<0.05) after AMI, while LVESV was significantly lower in HGF group than that in control group at 8 weeks after AMI (18.98+3.47 vs 25.66+5.86; P<0.05). Posterior left ventricular wail thickness decreased significantly from 1 wk to 8 wks after AMI in control group, while remained unchanged in HGF group.Compared with control group, histological examination showed more neovascularization and less scar, and sirius red staining indicated higher volume of type III collagen (7.10±4.06% vs 3.77+1.09%; P<0.05) and lower collagen I/III ratio value (1.11 ±0.52 vs 2.94±2.48; P<0.05) in HGF group. Conclusion HGF gene transfer might improve cardiac function and LV remodeling after acute myocardial infarction by stimulating angiogenesis, reducing fibrosis, and reducing myocardial scarring.