Effect of basic fibroblast growth factor on angiogenesis in ischeamic myocardium and cardiac function

AIM Therapeutic angiogenesis with growth factors has described a strategy where blood vessel formation is induced for the purpose of treating ischemic heart diseases.However,the delivery strategies to achieve clinically significant angiogenic responses are controversial.The aim of the present study was to evaluate the effect of intramyocardial injection of basic fibroblast growth factor on angiogenesis in infarcted myocardium and cardiac function.METHODS Twenty-four mongrel dogs were randomized into control group and therapeutic group.Acute myocardial infarction was made by ligation of the left anterior descending coronary artery distal to its first diagonal branch.After coronary artery was occluded,50 g of basic fibroblast growth factor(bFGF) in 15 ml of saline was injected into the infarcted myocardium and its peri-infarct region in therapeutic group,whereas 15ml saline alone was used in control dogs.Every 3 dogs in each group were studied on 0,2,9 and 16 day after surgery respectively.With sensitivity encoded technique,cine MR was performed on each dog before euthanasia to evaluate cardiac function.Electron microscope was used to observe the growth of capillaries.Angiogenesis was evaluated by immunohistochemical studies with Ⅷ factor.RESULTS In therapeutic group,LVEF improved markedly 9 days after injection of bFGF.The capillaries grew actively in therapeutic group and microvessel density was higher in therapeutic group than in control group but the first day(2 day:control group 92±12,therapeutic group 147±12;9 day:control group 125±12,therapeutic group 183±14;16 day:control group 125±14,therapeutic group 224±20).CONCLUSION Intramyocardial administration of bFGF is useful for increase in the growth of microvessels and improvement in left ventricular function in acute myocardial infarction.