The breakdown and recovery of blood-nerve barrier

本研究旨在揭示外周神经系统（PNS）免疫组化检查能否成为定量分析血神经屏障（BNB）及BNB修复与神经再生关系的可靠方法。神经挤压后对大鼠坐骨神经进行检查。采用识别内皮细胞的抗大鼠内皮细胞抗原-1 （anti-RECA-1）和检测屏障型内皮细胞的抗内皮屏障抗原（anti-EBA）免疫组化染色。对轴突进行抗神经丝染色。采用EBA阳性细胞与RECA-1阳性细胞的比例对BNB进行定量分析。术后第3天EBA/RECA-1比值显著下降，第7天在近端5mm节段和整个远端残端达到最低水平。该比值从近端逐渐恢复，轴突再生开始时间比BNB早一周。应用于PNS的EBA/RECA-1比值可作为定量分析BNB的可靠方法。在挤压伤中，近端5mm节段和远端整个残端同时发生BNB破坏；从近端到远端开始修复，一周后进行神经再生。

The purpose of this study is to reveal whether the application of immunohistochemical examinations to the peripheral nervous system (PNS) can be a reliable method for the quantitative analysis of the blood-nerve barrier (BNB) and the relationship between restoration of BNB and nerve regeneration. Sciatic nerves in rats were examined after nerve crush. Immunohistochemical staining with anti-rat endothelial cell antigen-1 (anti-RECA-1) that recognizes endothelial cells and anti-endothelial barrier antigen (anti-EBA) for the detection of barrier-type endothelial cells were used. Anti-neurofilament for staining axons was also performed. A quantitative analysis of the BNB was assessed using the ratio of EBA positive cells and RECA-1 positive cells. The ratio of EBA/RECA-1 decreased significantly three days postoperatively and reached its lowest level at day seven in the segment 5mm proximal and the entire distal stump. The ratio gradually recovered from the proximal and the regeneration of axons started a week earlier than BNB. The ratio of EBA/RECA-1 applied to the PNS can be a reliable method for the quantitative analysis of BNB. In crush injuries, the breakdown of BNB occurred simultaneously in the segment 5mm proximal and the entire distal stump ; restoration began from the proximal to distal and followed a week later to nerve regeneration.