早期细胞凋亡在创伤性脑损伤肠黏膜屏障应激性变化中的作用

The role of apoptosis in the stress-related changes of intestinal mucosa barrier following traumatic brain injury

目的 探讨早期细胞凋亡在创伤性脑损伤（TBI）大鼠肠黏膜屏障应激性变化中的作用.方法 选用雄性Wistar大鼠64只,随机分为TBI组（32只）和假手术对照组（32只）.2组大鼠分别按术后6、12、24和48 h时相点分为4个亚组（每个亚组8只）.在光镜和透射电镜下观察肠黏膜组织形态学变化,同时用Annexin Ⅴ-PI双染法经流式细胞仪检测各组早期细胞凋亡率.结果 光镜下TBI组可见肠黏膜上皮细胞受损,电镜下可见其细胞间紧密连接较假手术对照组增宽,并可见典型的凋亡细胞.TBI组的创伤后早期即可见肠黏膜细胞的凋亡率较假手术对照组明显升高[6 h：（13.5±3.7）%比（6.1±1.7）%,P＜0.05;12 h：（66.1±6.0）%比（5.2±1.1）%,P＜0.05;24 h：（39.8±4.8）%比（8.4±2.6）%,P＜0.05;48 h：（7.5±1.3）%比（6.6±0.5）%].结论 大鼠TBI后的早期,肠黏膜屏障功能即可受损,肠黏膜上皮细胞早期凋亡率的增加可能在这一病理生理过程中起着重要作用.

Objective To investigate the role of epithelial cell apoptosis in the stress-related changes of intestinal mucosa barrier following traumatic brain injury. Methods Sixty-four health male Wistar rats were divided randomly into two groups： （1） traumatic brain injury model group （n =32） ,in which rats suffered from traumatic brain injury by Feeney＇s method; （2） control group （ n = 32） , rats suffered from sham operation. Each group were divided into four subgroups according 6 h, 12 h,24 h, and 48 h after operation （ n = 8, for each subgroup ）. Ileum tissue were taken to observed the damage of the intestinal mucosa under microscope and electronmicroscope. The early apoptosis rate of intestinal mucosal cells were analyzed with Annexin Ⅴ-PI double stained and detected by flow cytometry. Results The intestinal mucosa were damaged and the intercellular space of intestinal mucosal were found increased in traumatic brain injury group. The early apoptosis rate of intestinal mucosal epithelial cells was significant increased in traumatic brain injury group than that in control group [6 h： （13.5 ±3.7）% vs （6.1 ± 1.7）%, P＜0.05; 12 h：（66.1±6.0）% vs （5.2±1.1）%, P＜0.05; 24 h：（39.8±4.8）% vs （8.4±2.6）%, P＜0.05;48 h： （7.5 ±1.3）% vs （6.6 ±0.5）%]. Conclusion The increased early apoptosis rate of intestinal mucosal epithelial cells might contribute to the stress-damage of the intestinal mucosa barrier in early stage of traumatic brain injury.