三种犬离体肺保存方式对肺表面活性物质的影响

Effect of Different Canine Isolated Lung Preservation Methods on Pulmonary Surfactant

为研究3种不同的犬离体肺保存方式对支气管肺泡灌洗液中肺表面活性物质的影响。随机将30只Mongrel犬分成3组,为体外循环灌注组、间断压力灌注组和单纯低温保存组,每组10只。在保持机械通气的条件下,摘取犬双肺,3种不同方式保存离体肺,按时间点留取支气管肺泡灌洗液标本,BCA法测定总蛋白浓度,抗坏血酸法测定总磷脂的含量,薄层色谱分析测定二棕榈酸磷脂酰胆碱含量,酶联免疫吸附试验检测白介素(IL-1a/2/6/8)。随着犬肺离体时间的推移,各实验组离体肺支气管肺泡灌洗液中DPPC/PL的比值呈时间依赖性下降,各白介素/总蛋白比值呈时间依赖性升高。在同一时间点上,体外循环灌注组中DPPC/PL的比值最高,间断压力灌注组次之,单纯低温保存组最低;体外循环灌注组中各白介素/总蛋白的比值最低,间断压力灌注组次之,单纯低温保存组最高。采用体外循环机持续灌注犬离体肺,离体肺中可维持较高浓度的肺泡表面活性物质,维持肺泡表面张力,发挥肺保护作用,这可能与抑制炎症介质的释放有关。

In order to study the effect of three different preservation methods of canine isolated lungs on pulmonary surfactant in bronchoalveolar lavage fluids, thirty Mongrel dogs were randomly divided into 3 groups which were extracorporeal circulation perfusion group, intermittent pressure perfusion group and simple low temperature preservation group, and each group were 10 canines. Both lungs were completely resected under the condition of keeping mechanical ventilation, and then the isolated lungs were preserved by three ways, and the specimens of bronchoalveolar lavage fluids were collected in light of the time point. The total protein concentration was measured by BCA. Antiscorbutate method was used to measure phospholipid （PL）. Thin-layer chromatography was used to detect L-alpha-Dipalmitoyl phosphatidylcholine （DPPC）. Interleukin （IL-1 a/2/6/8） were detected by ELISA. With the passage of the time of canine lung in vitro, DPPC/PL showed a trend of time-dependent decline, but the ratios of interleukin over total protein （TPr） were time-dependent increased in each experimental group. At the same time point, DPPC/PL in extracorporeal circulation group was the highest in three groups, and pressure perfusion group was higher than that of cold-storage preservation group; and the ratios of interleukin over TPr in extracorporeal circulation group were the lowest in three groups, and pressure perfusion group was lower than that of cold-storage preservation group. Using extracoporeal circulation machine continuous perfusion of canine lung in vitro could maintain stable pulmonary surfactant and alveolar surface tension, and play a role in lung protection. It may be related to inhibiting the release of inflammatory mediators.