肌苷对大鼠脑缺血再灌注后勿动蛋白基因表达的影响

①目的　探讨脑缺血再灌注后勿动蛋白 (Nogo A)基因表达的变化规律及肌苷对其表达的影响。②方法　成年健康雌性SD大鼠 6 0只 ,以线栓法建立大脑中动脉缺血再灌注模型。随机分为治疗组和对照组 ,每组再随机分为缺血 1.5h再灌注 2h、12h、1d、2d、3d、7d、14d组 (n =4 ) ,另外 4只作假手术组。应用Bederson等神经功能评分法评定脑缺血再灌注后各组大鼠神经功能的恢复情况 ,原位杂交技术检测脑组织Nogo AmRNA的表达。③结果　对照组在缺血侧皮质和纹状体区Nogo AmRNA表达于 12h和 2d呈双峰增高 ,神经功能于 3d开始恢复。肌苷治疗组与对照组比较 ,Nogo AmRNA在皮质区的表达于 12h增高 ,7d下降 ,在纹状体区 12h、2d、3d增高 (t=1.93～ 14 .96 ,P <0 .0 5 ) ;神经功能于 7d恢复 ,差异有显著性 (t =2 .31,P <0 .0 5 )。④结论　肌苷可促进大鼠脑缺血再灌注后神经功能恢复 ,其作用机制可能与Nogo AmRNA表达下调有关。

EFFECTS OF INOSINE ON EXPRESSION OF Nogo-A mRNA AFTER CEREBRAL ISCHEMIC REPERFUSION IN RATS

ObjectiveTo investigate the expression of Nogo-A mRNA after cerebral ischemic reperfusion and the effects inosine on the expression. MethodsThe model of the middle cerebral artery occlusion (MCAO) and reperfusion was established in 60 adult female SD rats by nylon monofilament suture. The rats were randomly divided into treated and control groups. The rats in each group was further divided into 2-, 12-hour, 1-, 2-, 3-, 7-, and 14-day reperfusion subgroups, and the other four rats were sham-operated. Bederson and other neurological gradings were applied to evaluate neurological function, and in situ hybridization was used to examine the expression of Nogo-A mRNA in the brain tissues. ResultsNogo-A mRNA expression showed two peaks at 12 hours and two days in ischemic cortex and striatum in the control group. When given inosine,Nogo-A mRNA expression transiently increased at 12 hours but decreased at seven days in ischemic cortex, but increased at two and three days in ischemic striatum (t=1.93-14.96, P<0.05). The neurological grade increased significantly at seven days(t=2.31,P<0.05). Conclusion Inosine can improve neurological grade of MCAO rats. The enhanced neurological function might be partially caused by the down-regulation of Nogo-A mRNA. [