神经节苷脂对脑缺血再灌注大鼠突触素p38表达的影响

Effect of ganglioside on expression of synaptophysin p38 in rats after cerebral ischemic reperfusion

目的:观察神经节苷脂对大鼠脑缺血再灌注后突触素p-38表达的影响。方法:成年健康雌性Wistar大鼠54只,随机分为神经节苷脂治疗组、对照组和假手术组,每组18只。采用线栓法建立大脑中动脉缺血再灌注动物模型,假手术组不插入尼龙线。神经节苷脂治疗组大鼠在大脑中动脉缺血再灌注手术前2h和术后每天脑室注神经节苷脂10g/L,对照组同步脑室注射等量10μL生理盐水,两组分别于治疗后6h,1,3,7,14,21d各取3只,40g/L多聚甲醛心脏灌注固定,取脑备用。假手术组不作处理,于相应时间点心脏灌注固定,取脑备用。应用免疫组织化学方法观察神经节苷脂对p-38表达的影响。结果:54只大鼠均进入结果分析。①大体观察:在大脑中动脉缺血再灌注24h后左侧大脑中动脉供血区脑组织肿胀、苍白,第7天可见顶叶颗粒状局部脑组织萎缩,第14天有坏死囊腔形成。②p38表达:假手术组在皮质、纹状体和海马区p38表达很弱,左右对称,其校正吸光度值在不同时间点比较,差异无显著性意义。对照组纹状体背外侧梗塞周围区,p38的免疫活性于再灌注6h和1d未出现明显变化,第3天可见升高,第7天达到高峰,第14天明显下降,第21天下降至假手术组水平。在缺血侧顶叶皮质亦可见到p38的免疫活性在3d后明显升高,在21d已接近假手术组水平。脑缺血再灌注3～7d,p38免疫活性最高,免疫产物的颗粒较大,其校正吸光度值显著高于假手术组(P<0.05)。脑室注射外源性神经节苷脂组,各脑区p38的表达较对照组略有增强,各个时间点的校正吸光度值与对照组比较差异无显著性意义。结论:脑室注射外源性神经节苷脂后,各脑区P38免疫反应活性有所增加,但差异不显著,不能得出神经节苷脂与P38的直接因果关系,亦不能断然否定两者间的内在联系。

AIM： To observe the effect of ganglioside （GM1） on the expressions of synaptophysin p38 after cerebral ischemic reperfusion in rats. METHODS： Totally 54 healthy adult female Wistar rats were divided randomly into GM1 group, control group and sham-operated group, with 18 rats in each. Filament method was applied to establish the middle cerebral artery occlusion （MCAO） models, but sham-operated rats were treated without filaments. At 2 hours before operation and post-operative everyday, the rats of GM1 group were given cerebroventricular infusion of 10 g/L GM1, while control rats were injected with 10 μL saline. Three rats were selected from each group at pest-operative 6 hours and 1, 3, 7, 14 and 21 days for 40 g/L formaldehydum heart infusion, and then brains were fetched for reserve. There was no treatment in the sham-operated group, only heart infusion was conducted at the corresponding time points for reserve. The effect of GM1 on the expressions of p38 was observed by immunohistochemical method. RESULTS： Totally 54 rats were involved in the result analysis.①General observation： After 24 hours pest-operative, there was swelled and pale brain tissues found in the blocd-supply area of left middle cerebral artery. On the 7^th day, local brain tissues atrophied in parietal lobe at granules, and necrosis Capsular cavity formed on the 14^th day. ②The expression of p38： In sham-operated group, the expressions of p38 were symmetrical and weak in the cortex, corpus striatum and hippocampus regions, and there was no significant difference in the corrected absorbance at different time points. In the control group, the immune activities of p-38 were stable around the infarction area of corpus striatum after 6 hours and one day post-operative, and elevated on the 3^nl day, peaked on the 7^th day, decrased obviously on the 14^th day, then decreased to the level of sham-operated group on the 21^nl day. As for the ischemic lateral parietal lobe cortex, the immunologic activity of p38 was notably enhanced at the 34 day, and similar to the level of the sham-operated group on the 214 day. The activity of p38 was the topmost from the 3^rd to 7^th day after cerebral ischemic reperfusion, with the immune products of large granules, and the corrected absorbance was remarkedly higher than that of sham-operated group （P 〈 0.05）. Compared with control group, the expression of p38 slightly increased after GM1 treatment, but the difference of corrected absorbance was not significant at the different time points. CONCLUSION： After cerebroventricular infusion of ectogenesis GM1, the immunologic reactive activity of p38 enhances, with the insignificant difference, however, it is not suggested that there is direct causality, or the absolutely negative internal correlation between GM1 and p38.