The Combined Administration of Multiple Soluble Factors in the Repair of Chronically Infarcted Rat Myocardium

The purpose of this study was to investigate a potential benefit of simultaneous administration of multiple soluble factors (SFs) in the repair of chronically infarcted rat myocardium. Rats subjected to a permanent coronary artery occlusion (myocardial infarction) received a cocktail of SF or a phosphate buffer. Four SFs, fibroblast growth factor-2 (2 μg), insulin-like growth factor-1 (1 μg), hepatocyte growth factor (2 μg), and stromal cell-derived factor-1α (0.6 μg) were injected directly into the ischemic myocardium at the onset of occlusion and subsequently at 3, 7, 14, and 21 days of surgery (intraperitoneally). Cardiac contractile function, infarct size and remodeling, and blood vessel density were studied at 4 weeks postsurgery. Infarct size, left ventricular circumference and cavity volume, thinning ratio, and expansion index were not statistically different between groups. Treatment of SF did not alter ejection fraction, compared with control. No statistical difference in total blood vessel density in the infarct zone was observed in SF versus control. In conclusion, our results that there were no enhancements in cardiac function, reductions in infarct size, improvements in remodeling, or increases in vasculature density in SF versus control do not support the study hypothesis that the combined use of multiple SF benefits the hearts with myocardial infarct.