Expression of nerve growth inhibitory factor Nogo-A after focal cerebral ischemia in rats

Objective To investigate the change in nerve growth inhibitory factor Nogo-A expression after middle cerebral artery occlusion(MCAO)for 120 minut in rats and the role of Nogo-A in the nerve regeneration.Methods 36 male SD rats weighing 260~280g were randomly divided into 6 groups:normal,MCAO 1d,MCAO 3d,MCAO 7d,MCAO 14d and MCAO 28d groups.Nogo-A positive cells in the ischemic striatum at different time points were observed using immunohistochemical method(n=3)and Nogo-A protein levels were detected by Western blot(n=3).Results The number of Nogo-A positive cells in the ischemic striatum began to increase at 1d,returned to the normal control level at 7d,then increased again at 14d and significantly decreased at 28d.This was consistent with the findings by Western blot.Conclusion The increase of Nogo-A expression in the early stage of MCAO(14d)might inhibit the nerve regeneration following ischemia;and the decrease in the late stage(28d)of ischemia might be involved in neural recovery and the formation of plasticity.