Abstract:

Objective    To study the effect of ischemic preconditioning ( IP) on expressions of vascular endothelial growth factor(VEGF) and matrix metalloproteinase-9(MMP-9) and the micro-vessel density(MCV) after focal cerebral infarction in rats, and to explore the mechanism of neuro-protection of IP on subsequent focal cerebral infarction. Methods    Transient middle cerebral artery occlusion(MCAO) for 10 min was used as IP , and reperfusion for 48 h was carried out after IP and before permanent MCAO(PMCAO) to produce ischemic tolerance(IT) .  Nerve function score, brain water content, pathological changes in cerebral tissues, expressions of VEGF and MMP-9, and MVD were detected. Results    IP significantly reduced neurological and histological injuries after PMCAO. Immunohistochemical examination revealed that 24 h after PMCAO, expression of MMP-9 in the IP experimental group was lower than that in the control group and the sham operated group, while VEGF expression and MVD were higher. Brain edema was reduced in the IP experimental group. Conclusion    IP can provide significant brain protection for subsequent PMCAO and induces IT in the brain. It provides dramatic protection through promoting angiogenesis.

Key words: Ischemic preconditioning; Ischemic attack, transient; Gelatinase B; Vascular endothelial growth factor; Angiogenesis