The effect and mechanism of VEGF/ERK Signaling Pathway on vasospasm after experimental subarachnoid hemorrhage.

[Objective] To investigate the molecular mechanism of VEGF /ERK Signaling Pathways for Early Brain Injury on subarachnoid hemorrhage after subarachnoid hemorrhage.[Methods] We made a stable and reliable rat SAH model by endovascular perforation without opening cranium,there were 24 male SD rats which were divided randomly into control groups,sham operated and SAH groups.After 24h operation,we used HE staining to observe the histological changes of middle cerebral arteries(MCA).The gene expression of VEGFmRNA at 24h after SAH was assayed by in situ hybridization.Western blot assay was used to examine the VEGF,p-ERK1 /2 expression,apoptotic cell number were determined by TdT-mediated dUTP-biotin nick end labeling(TUNEL).[Results] SAH produced severe acute vasospasm after 24h in the arteries cerebral.VEGF and pERK1 /2 expression was significantly increased(P﹤0.05,ANOVA) at the time of 24h after SAH.TUNEL revealed that apoptosis level of endothelial cells in group SAH was significantly increased than that in group control and group sham.The quantification of VEGF expression in MCA was positively correlated with the expressions of p-ERK1 /2(r = 0.722,P﹤0.01).[Conclusion] VEGF contributes to early braininjury after SAH and apoptotis of cerebral arteries endothelial cells by enhancing the activation of the ERK pathways.