亚硝酸钠对脑梗死后周细胞及室管膜下区神经发生的影响

目的探讨亚硝酸钠对脑梗死后周细胞及室管膜下区神经发生的影响。方法采用线栓法制备小鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型。采用随机数表法将66只小鼠随机分为假手术+溶剂组,脑梗死+溶剂组,脑梗死+亚硝酸钠组。脑梗死后第3天测定小鼠脑含水量及缺血周围区PDGFRβ+周细胞的数量,脑梗死后第7天采用免疫荧光测定BrdU^+/DCX^+神经母细胞,脑梗死后第1、3和7天采用五分法评估小鼠神经功能缺损。结果脑梗死后第3天,与假手术+溶剂组相比,脑梗死+溶剂组小鼠脑含水量明显增多,缺血周围区PDGFRβ+细胞数明显减少(P<0.05);应用亚硝酸钠后,脑含水量明显降低,PDGFRβ+细胞数明显增多(P<0.05)。脑梗死后第7天,与假手术+溶剂组相比,脑梗死+溶剂组小鼠BrdU^+/DCX^+神经母细胞的数量均明显增多;与脑梗死+溶剂组相比,脑梗死+亚硝酸钠组小鼠室管膜下区的BrdU^+/DCX^+神经母细胞的数量均明显增多(P<0.05)。脑梗死后第1和3天,脑梗死+溶剂组和脑梗死+亚硝酸钠组小鼠的神经功能缺损评分差异无统计学意义(P>0.05);但在第7天,脑梗死+亚硝酸钠组小鼠的神经功能缺损评分较脑梗死+溶剂组明显降低(P<0.05)。结论亚硝酸钠可促进脑梗死后周细胞的存活和室管膜下区神经发生。

Effect of sodium nitrite on pericytes and subventricular zone neurogenesis after stroke

Objective To investigate the effects of sodium nitrite on pericytes and subventricular zone(SVZ)neurogenesis after stroke.Methods The middle cerebral artery occlusion(MCAO)model was induced by suture method.Totally 66 mice were randomly assigned into sham+vehicle group,ischemic stroke+vehicle group,and ischemic stroke+sodium nitrite group.We assessed brain water content and the number of PDGFRβ+pericytes in peri-infarction zone on 3rd day after MCAO.We also measured the number of BrdU/doublecortin(DCX)-positive neuroblasts in SVZ on 7th day after MCAO.Five point scale was used to evaluate neurologic deficits on 1st,3rd and 7th day.Results On the third day after MCAO,compared with the sham+vehicle group,the brain water content of the ischemic stroke+vehicle group was significantly increased,and the number of PDGFRβ+cells within the peri-infarct area was significantly reduced(P<0.05).After treated with sodium nitrite,the brain water content significantly decreased,and the number of PDGFRβ+cells significantly increased(P<0.05).On the 7th day after MCAO,the number of BrdU^+/DCX^+neuroblasts in the ischemic stroke+vehicle group significantly increased compared with the sham+vehicle group;compared with the ischemic stroke+vehicle group,the number of BrdU^+/DCX^+neuroblasts within SVZ of mice from ischemic stroke+sodium nitrite group significantly increased.On 1st and 3rd day after MCAO,there was no significant difference in neurological deficit scores in mice with ischemic stroke+vehicle group and ischemic stroke+sodium nitrite group(P>0.05).But on 7th day after MCAO,the neurological deficit score of ischemic stroke+sodium nitrite group significantly lower than that of the ischemic stroke+vehicle group(P<0.05).Conclusion Sodium nitrite promotes pericytes survival and SVZ neurogenesis after stroke.