New method to improve the perfusion of a skeletal muscle in cardiomyoplasty -study of angiogenesis promoted by bFGF-.

点击翻译按钮获取中文摘要

Tissue blood flow is the major factor of the function of skeletal muscle. In latissimus dorsi cardiomyoplasty, the ligation of perforation vessels causes skeletal muscle graft ischemia, and it contributes to the fatigue and lower performance of the muscle graft. Vascular delay methods improve the ischemia of muscle graft, but it needs 4 to 8 weeks long and not sufficient for long term cardiac assistance. To establish new method to improve the perfusion of the graft, we investigated an influence of angiogenic factors (bFGF and VEGF) on ischemic tissue.1. Experiment on the angiogenesis promoted by bFGF in cardiomyoplasty : We developed bFGF slow release system applying thermal crosslinking heparinization method of collagen, and transplanted it between myocardium and latissimus dorsi muscle in cardiomyoplasty of five dogs. Four weeks after operation, macroscopic and microscopic examination was performed. At the bFGF transplanted site, connective tissue and vascular endothelial cell were increased. Moreover, many capillary formations were seen. These results suggest that bFGF promote angiogenesis and improve the perfusion of ischemic muscle.2. Collateral circulation development by electroporation-assisted VEGF cDNA-encoding plasmid injection : A naked VEGF165-encoding plasmid was injected intramuscularly [IM] into the ischemic hind limb muscles of Wistar/ST rats. Immediately, electoporation [EP] was added in the half of the groups. The effect was assessed by measuring blood pressure ratio [BPR] comparing to the opposite limb, and counting the number of vessels [angiographic score ; AS]. After gene transfer, the BPR and AS increased, and was higher in [IM+EP] group than in [IM] group. These results suggest that the feasibility of enhancing the efficiency of direct IM gene transfer of naked VEGF plasmid DNA for ischemic tissue, by electroporation.