局灶脑缺血/再灌注后nNOS、iNOSmRNA的表达

Temporal profile of nNOS,iNOSmRNA during the reperfusion after middle cerebral artery occlusion in rats

目的 :了解 n NOS m RNA和 i NOSm RNA在局灶性脑梗死表达中的时程变化与细胞定位。方法 :鼠局灶性脑缺血 /再灌注模型 ;用原位杂交技术进行缺血 /再灌注后 1,3,5天 n NOS m RNA、i NOSm RNA表达的细胞定位并用点杂交方法测量不同时间段梗死半球与非梗死半球内 n NOS m RNA、i NOSm RNA水平。结果 :正常鼠 n NOSm RNA以神经元表达为主 ,i NOSm RNA无表达 ,梗死后 i NOSm RNA表达以小胶质细胞为主 ,梗死区未见 n NOSm RNA;n NOSm RNA表达从 4h就开始下降 ,1～ 3天最低 ,5天左右又上升 ,i NOSm RNA在缺血再灌注后 12 h开始表达 ,1天左右升至高峰 ,3天左右缓慢下降。结论 :n NOSm RNA在缺血损伤后有一短暂表达增高 ,而在缺血损伤 4h后就开始缓慢下降 ;而 i NOSm RNA在缺血 /再灌注后 12 h开始表达 ,高峰在 1天左右 ,3天左右开始下降 ,其细胞定位以小胶质细胞为主。

Objective:To observe expression on time course changes and cell location of nNOS、iNOSmRNA during the reperfusion after focal cerebral ischemia in rats.Methods:We used the method of in situ hybridization(ISH) to determine which cell located in the ischemia area contained nNOSmRNA or iNOSmRNA on 1、3 and 5 day and measured the temporal profile of nNOSmRNA and iNOSmRNA by using the method of dot blot at different stages during the reperfusion after middle cerebral artery occlusion(MCAO) in rats.Results:The positive hybridizable signal of nNOSmRNA was not seen in the infarct area and that of iNOSmRNA was observed in microglias.The nNOSmRNA decreased within 4 hour and dropped to the lowest after 1～2 day and then started to upregulate again,The iNOSmRNA increased within 12 hour and rose to the peak after 24 hour and about 72 hour that downregulated slowly during the reperfusion in the ischemic ipsilateral after MCAO in rats.Conclusion:Combining with studies that we have done,the expression of nNOSmRNA upregualated 4 hour befor and downregulated in 4 hours,while that of iNOSmRNA upregulated in 12 houes and rose to the peak about 1 day and that downregulated in the third day in this ischemia/reperfusion model of rats.