三种方法复制'二次打击'急性呼吸窘迫综合征动物模型的比较与评价

摘要

Objective To find an ideal animal model of acute respiratory distress syndrome (ARDS) through investigating the characteristics of three "two-hit" animal models of ARDS.Methods Forty-eight SD rats were randomly divided into 4 groups: Control group [2.5 mL/kg normal saline (NS) i.v.given at 0 min and 30 min];OA+OA group [0.5 mL/kg oleic acid (OA) i.v.given at 0 min and 30 min];LPS+LPS group [2.5 mg/kg lipopolysaccharide (LPS) i.v.given at 0 min and 30 min];and OA+LPS group [0.5 mL/kg OA i.v.given at 0 min and 2.5 mg/kg LPS,i.v.given at 30 min].The samples were collected at 5 h after the second drug injection.White blood cells count (WBC),polymorphonuclear leukocyte ratio (PMN%),total protein concentration,tumor necrosis factor α (TNF-α) level in bronchoalveolar lavage fluid (BALF),arterial blood gas analysis and lung wet-dry weight ratio (W/D) were measured,respectively.Pathological changes in the lung tissues were observed and histological scores were evaluated.Results Compared with those in the control group,PaCO2,WBC,PMN%,total protein concentration and TNF-α levels in BALF were significantly increased,while PaO2 was dramatically decreased (P<0.01) in the OA+OA,LPS+LPS and OA+LPS groups.The levels of protein concentration in BALF and lung W/D ratio in the OA+LPS group were significantly higher than these in the LPS+LPS group (P<0.05 for all),but had no statistically significant difference compared with these in the OA+OA group.The levels of WBC,PMN% and TNF-α in BALF in the OA+LPS group were significantly higher than those in the OA+OA group (P<0.05),but not significantly different from those in the LPS+LPS group.The most typical pathological changes and the highest pathological scores were found in the OA+LPS group.Conclusions All the three different methods including OA+OA,LPS+LPS,and OA+LPS can be used to establish “two-hit” animal models of acute respiratory distress syndrome.The “two-hit” animal model of acute respiratory distress syndrome induced by OA+LPS is more closer to clinical ARDS and is useful for studies on the pathophysiology of ARDS,and is an ideal “two-hit” animal model of ARDS.%目的 通过研究三种不同"二次打击"急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)动物模型的特点,寻找较为理想的ARDS动物模型.方法 将48只大鼠随机分为4组,每组12只.对照组(Control组):尾静脉先注射生理盐水(normal saline,NS)2.5 mL/kg,30 min后注射NS 2.5 mL/kg;油酸+油酸组(OA+OA组):尾静脉先注入OA 0.05 mL/kg,30 min后继续注射OA 0.5 mL/kg;内毒素+内毒素组(LPS+LPS组):尾静脉先注入LPS 2.5 mg/kg,30 min后继续注射LPS 2.5 mg/kg;油酸+内毒素组(OA+LPS组):尾静脉先注入OA 0.05 mL/kg,30 min后注射LPS 2.5 mg/kg.5 h后处死动物采集标本,检测动脉血气,支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中白细胞总数、多形核白细胞百分比(polymorphonuclear leukocyte ratio,PMN%)、肿瘤坏死因子(tumor necrosis factor α,TNF-α)水平、总蛋白含量,肺干湿重比(lung wet-dry weight ratio,W/D),观察肺组织病理改变并进行肺损伤评分.结果 与control组比较,LPS+LPS组、OA+OA组及OA+LPS组的氧分压(PaO2)下降(P<0.05)、二氧化碳分压(PaCO2)、BALF中白细胞总数、PMN%、TNF-α、总蛋白含量,W/D、肺损伤评分均升高(P<0.05).OA+LPS组总蛋白含量、W/D均高于LPS+LPS组,差异有显著性(P<0.05),而与OA+OA组比较则差异无显著性;OA+LPS组BALF中白细胞计数、PMN%、TNF-α较OA+OA组高(P<0.05),而与LPS+LPS组比较则差异无显著性;OA+LPS组肺病理改变最典型,肺损伤评分最高.结论 OA+OA、LPS+LPS和OA+LPS复合打击法均可建立"二次打击"ARDS大鼠模型,其中OA+LPS复合打击法所复制的ARDS模型与临床ARDS特点更为接近,有利于研究ARDS的病理生理过程,是一种较为理想的"二次打击"ARDS动物模型.