The study of angiogenesis induced by electrical stimulation below contraction threshold,in ischemic myocardium / 重庆医科大学学报

ABSTRACT

Objective:To study the ischemic myocardial angiogenesis induced by electrical stimulation below contraction threshold.Methods:24 infarcted rats were given electrical stimulation below contraction threshold for 5 days with 10Hz,15Hz,25Hz,50Hz stimulus frequencies.12 other infarcted rats were electrically stimulated with effective stimulus frequency which induced myoardial angiogenesis and treated with VEGF neutralizing antiboby,L-NAME for 5 days.Capillary density(CD),activity of NOS,expression of VEGF mRNA and protein,were detected.Results:CD,activity of NOS,expression of VEGFmRNA and protein in ischemic myocardium were significantly augmented in the 25Hz group compared with the other groups.CD and activity of NOS in ischemic myocardium significantly decreased in 25Hz+VEGF neutralizing antibody group compared with that of the 25Hz group.CD in ischemic myocardium significantly decreased in the 25Hz+L-NAME group compared with that of the 25Hz group,but expression of VEGF mRNA and protein were in the absence of changes the 2 groups.Conclusion:Myocardial angiogenesis induced by electrical stimulation below contraction threshold at 25Hz frequeney is dependent on the expression of VEGF.Nitric oxide can mediate mitogenic effect of VEGF on capillary endothelial cells.