Abstract：Objective: To study the dose-effectiveness of the vascular endothelial growth factor(VEGF) in focal cerebral ischemia reperfusion injury of rabbits by MR imaging. Methods: Rabbit model of focal cerebral ischemia was induced by occlusion of the middle cerebral artery for 2 hours. The VEGF was administered immediately after reperfusion at different doses. We measured infarct volume, neural cell apoptosis, activation of caspase-3 and ADCR in the perifocal regions of cerebral ischemia and neurological deficit score 72h after reperfusion. Results: There was no significant difference in the cerebral edema, neuroprotective efficacy and angiogenesis at the dose of 1.25ng/μl VEGF compared with control group. When administered VEGF at the dose of 2.5ng/μl and 5.0ng/μl after reperfusion, the cerebral edema, the percentage of apoptotic cell and activation of caspase-3 in the perifocal regions were lowered significantly, the ADCR and increase of blood vessels were significantly higher than those in the control group. The neuroprotective efficacy and significant enlargement of the blood vessels were observed in the 2.5ng/μl than that in 5.0ng/μl group, and the infarct volume was significantly reduced in the 2.5ng/μl group(P<0.05). Conclusions: The VEGF at a dose of 2.5ng/μl has displayed excellent increase in vessel density and neuroprotective efficacy for focal cerebral ischemia reperfusion injury of rabbits. Therefore, the dose of 2.5ng/μl was used in the following treatments to further evaluate the effect of VEGF.
2006, Vol. 17 
