创伤性脑损伤合并海水淹溺大鼠脑水肿的时程变化

The time course changes of brain edema in rats with traumatic brain injury complicated by seawater drowning

目的通过检测创伤性脑损伤(traumatic brain injury,TBI)合并海水淹溺(seawater drowning,SWD)大鼠伤后不同时间点的脑组织含水量、Na^+、K^+离子含量及血脑屏障(BBB)通透性,探讨此类复合伤后脑水肿的时程变化。方法216只SD大鼠随机分为对照组(n=6)、假手术(Sham)组(n=14)、TBI组(n=98)、TBI+SWD组(n=98)。采用Marmarou颅脑致伤法及气管内泵入海水法建立TBI+SWD大鼠模型。采用干湿质量法、火焰分光光度法、伊文思蓝(Evans blue,EB)染色法分别检测脑组织含水量、Na^+、K^+离子含量及BBB通透性。结果TBI组脑组织含水量、Na^+含量在伤后12 h开始明显增高,伤后2~3 d达到峰值,伤后14 d恢复正常;K^+含量伤后12 h开始降低,2~3 d达到最低点,7 d仍低于正常水平;EB含量增高且呈双高峰,分别出现在伤后3 h及伤后2 d,后者峰值更高。TBI+SWD组伤后脑组织含水量、Na^+及EB含量较TBI组明显增高,而K^+含量较TBI组明显降低。TBI+SWD组伤后脑组织含水量、Na^+含量在伤后3 h开始增高,12 h达到峰值且持续到伤后7 d、14 d仍高于正常水平;脑组织K^+含量在伤后3 h明显下降,12 h达到低谷,持续到3 d,伤后7 d仍明显低于正常水平;脑组织EB含量伤后3 h明显增高,伤后12 h达到峰值,持续到伤后3 d,伤后14 d仍高于正常水平。结论SWD加重TBI大鼠的脑水肿反应。TBI+SWD大鼠伤后早期即出现严重的脑水肿反应且持续时间长。

Objective To detect the contents of brain water,Na^+,and K^+and the permeability of blood brain barrier(BBB)of the rats with brain edema in traumatic brain injury(TBI)complicated by seawater drowning(SWD)at different time points,so as to analyze the time course changes of brain edema after the combined injury.Methods A total of 216 SD rats were randomly divided into control group(n=6),sham operation group(n=14),TBI group(n=98),and TBI+SWD group(n=98).The TBI+SWD rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump.Dry-wet mass method was used to detect the content of brain water.Flame spectrophotometry method was used to detect the contents of Na^+and K^+.Evans blue(EB)staining method was used to detect BBB permeability.Results In the TBI group,the contents of brain water and Na^+began to rise obviously 12 h after injury,reached the peak 2-3 d after injury,and returned to the normal levels 14 d after injury.The content of K^+showed a fall 12 h after injury,reached the lowest point in 2-3 d after injury,and was still at a lower level than normal in 7 d.The EB content showed double peaks in 3 h and 2 d after injury respectively,and the latter peak was higher.Compared with those in the TBI group,the contents of brain water,Na^+,and EB in the TBI+SWD group were significantly increased,but the content of K^+was obviously decreased.In the TBI+SWD group,the contents of brain water and Na^+began to rise 3 h after injury,reached the peak at 12 h till 7 d after injury,and were still higher than the normal levels 14 d after injury.The content of brain K^+showed an obvious fall 3 h after injury,reached the lowest point at 12 h till 3 d,and was still lower than the normal level 7 d after injury.The EB content increased obviously 3 h after injury,reached the peak at 12 h till 3 d after injury,and was still higher than the normal level 14 d after injury.Conclusion SWD aggravates brain edema in TBI rats.TBI+SWD rats may develop severe cerebral edema in the early period after injury,which last for a longer time.