Liu H M, Lei H Y, Schmid K
Department of Pathology, National Cheng Kung University, Medical College, Tainan, Taiwan, Republic of China.
Lab Invest. 1993 May;68(5):577-83.
The aim of the present study is to demonstrate the distribution and quantitative changes of alpha 1-acid glycoprotein (AGP) in rat sciatic nerve subsequent to mechanical injury. AGP is a serum protein, whose level rises after injury; hence the term "acute phase reactant." AGP is synthesized mainly by hepatocytes and the production is stimulated by cytokines released by inflammatory cells. The biologic role of AGP is not known except that it has in vitro nerve growth promoting property.
Impermeable silicone tubes, 10 mm long and 1.4 mm in internal diameter, were sutured to the ends of transected rat sciatic nerve. On the 1st to 21st postoperative days, the wound fluid in the tube and the rat sera were collected for protein analysis and quantitative determination of AGP. The sciatic nerves were removed and immunostained with a monoclonal antibody against rat AGP.
The protein content in the wound fluid was 1/5 that of the serum, the proteins of the wound fluid and the serum had similar electrophoretic patterns on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There was a parallel rise of AGP levels in serum and in wound fluid beginning 1 day after the operation reaching the highest level on the 5th day. Immunohistochemical study showed deposits of extravasated AGP in fibrin cable connecting the ends of the transected nerve, in endoneurium, perineurium, perivascular mononuclear, and mesenchymal cells of epineurium at the wound and diffusely in the entire distal nerve segment.
Increased vascular permeability with exudation of leukocytes and plasma proteins are basic pathophysiologic reactions to injury. The wound chamber method employed in the present study may provide a useful model for investigations dealing with the roles of circulating plasma proteins and other molecules as well as local cellular products involved in wound healing and nerve regeneration.
本研究的目的是证明大鼠坐骨神经机械损伤后α1-酸性糖蛋白（AGP）的分布及定量变化。AGP是一种血清蛋白，其水平在损伤后升高，因此被称为“急性期反应物”。AGP主要由肝细胞合成，其产生受炎症细胞释放的细胞因子刺激。除了具有体外促进神经生长的特性外，AGP的生物学作用尚不清楚。
将内径为1.4mm、长10mm的不可渗透硅胶管缝合到切断的大鼠坐骨神经两端。在术后第1至21天，收集管内伤口液和大鼠血清用于蛋白质分析及AGP的定量测定。取出坐骨神经，用抗大鼠AGP单克隆抗体进行免疫染色。
伤口液中的蛋白质含量是血清的1/5，伤口液和血清中的蛋白质在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳上具有相似的电泳图谱。血清和伤口液中AGP水平从术后第1天开始平行升高，在第5天达到最高水平。免疫组织化学研究显示，渗出的AGP沉积在连接切断神经两端的纤维蛋白索中、伤口处的神经内膜、神经束膜、血管周围单核细胞以及神经外膜的间充质细胞中，并在整个远端神经段中弥漫分布。
血管通透性增加伴白细胞和血浆蛋白渗出是损伤后的基本病理生理反应。本研究采用的伤口腔室法可能为研究循环血浆蛋白和其他分子以及参与伤口愈合和神经再生的局部细胞产物的作用提供一个有用的模型。
