康复训练对脑梗死大鼠微血管超微结构及CD31表达的影响

The effects of rehabilitation training on microvessel ultrastructure and expression of CD31 in rats with focal cerebral infarction

目的研究康复训练对脑梗死大鼠梗死边缘区微血管生成及其超微结构以及血小板内皮细胞黏附分子-1（CD31）表达的影响。方法采用线栓法制作大鼠左侧大脑中动脉闭塞（MCAO）模型。60只成年SD大鼠随机分成康复训练组（n=30）和对照组（n=30）。另选6只大鼠作为假手术组。康复训练组从术后48h开始每天予以转棒、平衡木、滚筒等训练；对照组和假手术组则置于普通笼内饲养，不予以任何针对性训练。3组大鼠在造模术后第3，7，14天灌注、固定并取材，以透射电子显微镜观察脑梗死边缘区微血管的形态学改变；同时采用CD31标记微血管，以免疫组织化学法及免疫印迹法检测梗死边缘区CD31蛋白的表达。结果①透射电镜观察下，康复训练组大鼠随着训练时间的延长其梗死边缘区的毛细血管内皮细胞水肿情况减轻，细胞核及核仁的形态逐渐恢复，基底膜层的吞饮小泡明显减少，优于对照组。②康复训练组与对照组大鼠脑梗死边缘区标记微血管的CD31于造模术后第3天均有表达，第7天达峰值，第14天CD31的表达明显回落；康复训练组各时间点CD31表达均高于对照组，统计学分析显示，于造模后第7天时2组差异有统计学意义（P〈0．05）。结论康复训练能促进脑梗死边缘区微血管超微结构的恢复及新生血管的生成，这可能是康复训练促进受损神经功能恢复的机制之一。

Objective To study the effects of rehabilitation training on angiogenesis and its uhrastructure and expression of CD32 in the peri-infarction region of rats with focal cerebral infarction. Methods Sixty-six Sprague-Dawley rats with experimental left middle cerebral artery occlusion （MCAO） were used as subjects in this study. All the rats were randomly divided into three groups ： a rehabilitation training group （ n = 30） , which was given bar rotating, balancing and rolling exercises everyday after 48 hours post MCAO; a control group （n = 30） and a shamoperated group （n = 6） , which were fed in cages with no special training exercises. Then brain tissues were fixed on the 3rd d, 7th d, 14th d after MCAO, for observing the morphological alterations of microvessels in peri-infarction re gion using transmission electron microscope, immunohistocbemistry and Western blotting were used to measure the expression of CD31, which acted as the marker of the neogenetic microvessels. Results （ 1 ） It showed that the capillary endothelial cells were less edematous in the rehabilitation training group, and there were less pinocytosis bullae in basal membrane more integral nucleus of endothelial cells in rehabilitation training group when compared with those in the control group. （2） Expression of CD31 can be observed in peri-infarction region in both groups from the 3rd d onwards, and peaked on the 7th d, and then gradually went down after the 14th d. Comparison between the 2 groups showed that the expression of CD31 in rehabilitation training group was higher than that in the control group at every time point, but statistical difference between the 2 groups in this regard could be revealed only on the 7th d （P 〈 0,05）. Conclusion Rehabilitation training could promote ultrastructural recovery of microvessels and induce anglogenesis in peri-infarction region, and it might be one of the mechanisms of neural functional recovery in rats after MCAO,