The Effects Of Weekly Myocardial Ischemic Burden On Expression Of VEGF In Myocardium Of Rabbits

Objective: To investigate the effects of weekly myocardial ischemic burden on expression of vascular endothelial growth factor(VEGF) in hearts of rabbits.Methods: Thirty-five adult New Zealand rabbits (2.2-2.5kg) were randomly divided into the control group, sham-operated group and ischemic groups which were subdivided into 3, 5 and 7-day subgroups in terms of the weekly frequencies of ischemic stimulation. Controlled myocardial ischemia model was established by installing a balloon occluder on the left ventricular branch(LVB). Upon a seven-day postoperative recovery, 2-min occlusions per hour on LVB with different weekly ischemic burdens by inflating the balloon occluder were performed twice a day and lasted for 4 weeks, meanwhile ECG was observed. The ischemic myocardium was sampled for histological examination. The expression levels of VEGF in ischemic and non-ischemic myocardium were quantified by Western Blot. Results: â‘ The inflation of the balloon occluder momentarily induced elevation of ST segment, indicating safe and effective onset of myocardial ischemia. â‘¡ Compared with control and sham-operated group, the expression of VEGF obviously increased in the ischemic...