目的研究体外培养星形细胞牵张损伤后超微结构的变化。方法取新生1~2 d大鼠的皮层细胞原代培养,经纯化后传代培养于乳胶膜培养皿中。采用计算机控制的牵张损伤装置,分别以50、150、250 kPa压力牵张损伤培养于乳胶膜上的大鼠皮层星形胶质细胞。用3%戊二醛固定后,行扫描电镜和透射电镜观察。结果当用50 kPa驱动压力进行牵张损伤时,细胞结构即有明显破坏,表现为细胞间隙增宽,部分胞体和突起被撕裂;以50 kPa牵张损伤后1 h,透射电镜下可见线粒体肿胀、嵴减少;损伤后6 h可见线粒体致密、细胞器减少等。当牵张应力增大,星形细胞损伤程度加重,细胞器明显减少,线粒体空泡化,微丝、微管明显减少,直至水样胞质或致密胞体。结论较小的应力即可致星形细胞紧密连接的破坏和超微结构的改变,可能与脑外伤后产生广泛的脑水肿有关。 Objective To study the ultrastructural changes of astrocytes after stretch injury in vitro. Methods Cortical cells of neonatal rats were cultured in primary culture for 1-2 days. After purification, subcultured in latex membrane culture dishes. A computer-controlled stretch injury device was used to stretch and injure the rat cortical astrocytes cultured on the latex membrane at 50, 150 and 250 kPa respectively. After fixation with 3% glutaraldehyde, scanning electron microscopy and transmission electron microscopy were performed. Results When stretch injury was induced by 50 kPa driving pressure, the cell structure was obviously destroyed. The cell gap was widened and some cell bodies and protrusions were torn. At 1 h after stretch at 50 kPa, the mitochondria Swelling, crest reduction; 6 h after injury mitochondria can be seen dense, organelles and so on. When stretch stress increased, astrocyte injury increased, organelles decreased significantly, mitochondria vacuolization, microfilaments, microtubules significantly reduced until the water-like cytoplasm or dense cell body. Conclusion Smaller stress can cause the destruction of astrocyte tight junction and the ultrastructural changes, which may be related to the extensive brain edema after traumatic brain injury.