大鼠不同程度创伤性脑损伤后肠黏膜屏障的应激性变化

Stress-related changes of intestinal mucosa barrier following graded traumatic brain injury in rats

目的探讨大鼠不同程度创伤性脑损伤(TBI)后肠黏膜屏障(IMB)的应激性变化。方法健康清洁级Sprague-Dawley大鼠78只,随机分为无脑损伤的对照组(n=6)和轻、中、重度TBI组,再分别按伤后3、12、24、72h时间点分为4个亚组(n=6)。参照Feeney’s方法建立轻、中、重度TBI模型,光学显微镜下观察各组肠黏膜组织形态变化并检测血浆D-乳酸(D-LAC)、门静脉血内毒素(ET)水平、血浆二胺氧化酶(DAO)活性。结果与对照组比较:轻度TBI组伤后24h肠黏膜损伤指数(MDI)、D-LAC、ET水平、DAO活性均升高(P<0.05),伤后72h均回落与对照组无明显差异。重度TBI组伤后3h MDI、D-LAC、ET水平、DAO活性均明显升高(P<0.01),至伤后72h仍明显高于对照组(P<0.01)。中度TBI组上述指标介于轻、重度TBI组之间。结论大鼠不同程度TBI后发生不同程度肠黏膜结构损伤和屏障功能障碍。轻度TBI伤后24h出现一过性肠黏膜结构损伤和屏障功能障碍。中、重度TBI肠黏膜结构损伤和屏障功能障碍发生早并持续至伤后72h。

Objective To study the stress-related changes of intestinal mucosa barrier（IMB）following graded traumatic brain injury（TBI）in rats.Methods Seventy-eight healthy Sprague-Dawley rats were randomly divided into four groups： control group（n=6）,mild TBI（n=24）,moderate TBI（n=24）,severe TBI group（n=24）.TBI groups were further divided into four sub-groups for assessment at 3h,12h,24h and 72h post-injury（n=6 per group）,respectively.TBI model of rats was referred to the Feeney＇s method.Intestinal mucosal histology was determined by light microscope and plasma concentrations of D-lactate（D-LAC）,diamine oxidase（DAO） and endotoxin（ET） in portal blood were detected.Results In mild TBI group,the mucosal damage index（MDI）,the level of D-LAC and ET,the activity of DAO at 24h post-injury were significantly higher than those in control group,respectively（P0.05）.At 72h post-injury,they all decreased and the difference between mild TBI group and control group was not statistically significant.In severe TBI group,the MDI,the level of D-LAC and ET,the activity of DAO at 3h post-injury were significantly higher than those of control group,respectively（P0.01）.At 72h post-injury,they were all significantly higher than those in control group,respectively（P0.01）.In moderate TBI group,the data of all index were between mild TBI group and severe TBI group.Conclusion Graded damages of intestinal mucosal structure and barrier dysfunction occur following TBI with varying degrees.The mild TBI group shows transient damage of intestinal mucosal structure and barrier dysfunction which occur at 24h post-injury and recover to be normal at 72h post-injury.The moderate and severe TBI groups show damage of intestinal mucosal structure and barrier dysfunction which occur as early as 3h post-injury and last for more than 72h post-injury.