目的 建立一种创伤性脑损伤合并海水淹溺性急性肺损伤大鼠模型.方法 雄性SD大鼠80只按照数字表法随机分为4组:假手术(Sham)组、创伤性脑损伤(TBI)组、海水淹溺性急性肺损伤(SWD-ALI)组、创伤性脑损伤合并海水淹溺性急性肺损伤(TBI+SWD-ALI)组,每组20只.参照Marmarou颅脑致伤法(致伤量为450 g×1.5 m)建立TBI组;经气管内泵入配方海水(3 ml/kg)建立SWD-ALI组;在TBI的基础上建立TBI+ SWD-ALI组.监测伤后10、30、60、120、240 min时间点的动脉血气,伤后240 min时对肺组织湿干质量进行测定及行HE染色观察病理改变,伤后24h对脑组织行HE染色观察病理改变及行免疫组化染色观察β-APP和NF-L表达情况.结果 TBI、SWD-ALI、TBI+SWD-ALI组大鼠伤后观察期间PaO2总体呈升高趋势:伤后10 min时最低,分别为(85.12 ±2.03)、(37.75±1.17)、(33.38±1.92) mmHg,均明显低于Sham组[(95.25 ±2.05) mmHg] (P<0.05);240 min时最高,分别为(96.63±1.60)、(86.13 ±2.03)、(77.25±3.33) mmHg,SWD-ALI、TBI+ SWD-ALI组显著低于Sham组[(97.50±1.20) mmHg] (P <0.05),TBI+ SWD-ALI组显著低于SWD-ALI组(P<0.05).伤后240 min时各组大鼠肺组织湿干质量比比较:SWD-ALI组(7.30±0.16)、TBI+ SWD-ALI组(7.34±0.21)均显著高于Sham组(4.81±0.18)和TBI组(4.91±0.18)(P<0.05);SWD-ALI组与TBI+ SWD-ALI组差异无统计学意义(P>0.05).SWD-ALI、TBI+ SWD-ALI组大鼠肺组织HE染色均可见不同程度肺泡间隔增宽、肺泡腔融合、炎性细胞浸润等急性肺损伤的表现.TBI、SWD-ALI、TBI+ SWD-ALI组大鼠脑组织HE染色均可见大脑皮质神经元细胞变性,且TBI、TBI+ SWD-ALI组免疫组化染色可见β-APP、NF-L表达.结论 以450 g×1.5 m的致伤量致伤大鼠颅脑,继而经气管内泵入3 ml/kg配方海水的方法可建立稳定性、重复性好的创伤性脑损伤合并海水淹溺性急性肺损伤大鼠模型.
Objective To establish an animal model of traumatic brain injury coupled with acute lung injury induced by seawater drowning.Methods A total of 80 male Sprague-Dawley rats were randomly divided into 4 groups:the sham group,the traumatic brain injury (TBI) group,the seawater drowning-induced acute lung injury (SWD-ALI) group and the traumatic brain injury coupled with seawater drowning-induced acute lung injury (TBI + SWD-ALI) group,each consisting of 20 animals.The TBI model group was established with the impact power of 450 g × 1.5 m by the " Marmarou method".The SWD-ALI group was established by pumping the artificial seawater into the rat trachea at a rate of 3 ml/kg.The TBI + SWD-ALI group was established on the basis of TBI.The data of arterial blood gases were detected 10,30,60,120 and 240 minutes after trauma injury.Wet/dry weight of the lung was detected 240min after injury,and pulmonary pathological changes were also observed after HE staining.Pathological changes in the brain tissue after HE staining and the expression levels of/3-APP and NF-L after immunohistochemical (IHC) staining were observed 24 hours after injury.Results The levels of PaO2 after injury during observation period generally displayed an increasing trend in the TBI,the SWD-ALI and the TBI + SWD-ALI groups.The levels of PaO2 10 minutes after injury were the lowest,which were respectively (85.12 ± 2.03) mmHg,(37.75 ± 1.17) mmHg and (33.38 ± 1.92) mmHg,and were obviously lower than that of the sham group (95.25 ± 2.05) mmHg,with statistical significance (P<0.05).The levels of PaO2 at the time point of 240 minutes after injury reached peak,which were respectively (96.63 ± 1.60) mmHg,(86.13 ± 2.03) mmHg and (77.25 ± 3.33) mmHg,and the levels of PaO2 for the SWD-ALI and TBI + SWD-ALI groups were significantly lower than that of the sham group [(97.50 ± 1.20) mmHg],also with statistical significance (P < 0.05).The levels of PaO2 in the TBI + SWD-ALI group was considerably lower than that of the SWD-ALI group (P < 0.05).The ratios of wet/ dry weight of the lung tissue at the time point of 240 minutes after injury for the SWD-ALI group and the TBI + SWD-ALI group were respectively (7.30 ± 0.16) and (7.34 ± 0.21),which were all obviously higher than those of the sham group (4.81 ±0.18) and the TBI group (4.91 ±0.18),also with statistical significance (P < 0.05).However,no statistical significance could be seen,when comparisons were made between the SWD-ALI and TBI + SWD-ALI groups (P > 0.05).HE staining indicated that such pulmonary pathological lesions as wider alveolar septa,alveolar space fusion,inflammatory cell infiltration in various degrees could be observed in the SWD-ALI and TBI + SWD-ALI groups.In addition,brain tissue HE staining revealed that neuronal cell degeneration in the cortex of the brain tissue could be detected in the TBI,SWD-ALI and TBI + SWD-ALI groups,and immunohistochemical staining indicated that there were positive expressions of β-APP and NF-L in the TBI and TBI + SWD-ALI groups.Conclusion The impact with the power of 450 g × 1.5 m by the "the Marmarou method" followed by pumping of seawater (3 ml/kg) into trachea could establish a stable and reproductive rat model of traumatic brain injury coupled with acute lung injury induced by seawater drowning.