严重烫伤早期大鼠脑内MMP-9的表达及意义

Expression and Significance of Brain MMP-9 in Rats at the Early Stages of Severe Scald

目的:探讨MMP-9与严重烫伤后血脑屏障损伤的关系。方法:健康SD大鼠随机分为正常组、假烫伤组、烫伤组,烫伤后又设3、6、12、24、48 h 5个时相点,用透射电镜观察血脑屏障超微结构变化;干湿重法测脑含水量;紫外光度计检测脑EB含量;免疫组化观察脑MMP-9表达。结果:烫伤后大脑皮质的神经细胞线粒体肿胀或溶解,突触小泡减少,突触间隙增宽。脑毛细血管周围出现空泡化,内皮肿胀,基底膜厚薄不均。严重烫伤后脑含水量和EB含量明显增高,MMP-9表达升高,差别具有统计学意义(P<0.01)。结论:严重烫伤后大鼠血脑屏障通透性增高与脑内MMP-9表达升高有关,提示MMP-9是严重烫伤后血脑屏障损伤的关键因素。

AIM： To address whether BBB dysfunction caused by scald is associated with MMP- 9 overexpression. METHODS： Healthy SD rats were divided into three groups as following： normal control, sham - scalded group, scald group, scald group were quantified at 3, 6, 12, 24, and 48 h post thermal injury. The uhrastructural change of blood brain barrier was observed by transmission electron microscope; Brain water content was detected by calculating dry/wet weight; The change of brain MMP - 9 expression after severe scald was determined by immunohistochemical method. RESULTS： Brain water content was significantly increased after burn. Expression of brain MMP - 9 in rats after severe scald was higher than that of sham control group＇s, and the difference was considered significantly （ P 〈0. 01 ） . Under transmission electron microscope, mitochondrion of some neurons of the cerebral cortex were swollen or dissolved, the number of synapse vesicle decreased and synaptic cleft broadened. There were vacuolated, swollen endothelium, abnormity of capillary basement membranes of BBB. CONCLUSION ： The increase in MMP - 9 expression, associated with increased BBB permeability following thermal injury, indicates that MMP - 9 may contribute to observed BBB disruption in peripheral thermal injury.