白细胞滤过器保护肺功能的实验研究

EXPERIMENTAL STUDY ON THE PROTECTIVE EFFECT ON THE PULMONARY FUNCTION BY LEUKOCYTE DEPLETION

在猫体外循环 (CPB)动物模型基础上应用白细胞滤过器 (LDF) ,探讨LDF在CPB中肺保护的效果。实验组 (6只 )应用LDF ,对照组 (6只 )未用LDF。测定肺内白细胞扣留率 ,肺组织干 /湿重比值 ,用电子自旋共振 (ESR)法直接测定肺组织氧自由基含量 ,测定肺组织丙二醛 (MDA)含量 ,观察肺组织超微结构的变化。白细胞滤除率为 0 .93± 0 .0 5 ,与滤过前比较P <0 .0 1。肺内白细胞扣留率对照组明显高于实验组 (P <0 .0 1)。肺组织干 /湿比值对照组为 0 .2 5 8± 0 .0 11,实验组为 0 .6 12± 0 .0 2 3(P <0 .0 1)。在不同时间点对照组氧自由基含量均明显高于实验组 (P <0 .0 1) ;肺组织MDA的变化对照组由阻断前的 0 .5 74± 0 .0 5 1nmol/mg增至 1.371±0 .0 78nmol/mg(P <0 .0 1) ,6 0min后增至 2 .0 89± 0 .10 8nmol/mg ;实验组阻断前为 0 .5 2 3± 0 .0 48nmol/mg ,6 0min后为 0 .5 87± 0 .0 5 6nmol/mg ,实验组较对照组含量低 (P <0 .0 5 )。CPB后两组均可见肺泡水肿 ,有时可见透明膜形成 ,并伴有不同程度的白细胞浸润 ,以对照组最明显。研究表明 ,应用LDF能明显减轻肺损伤 ,具有较好的肺保护效果。

Leukocyte depletion filter (LDF) was used in a cardiopulmonary bypass (CPB) model in cat, and its protective effect of leukocyte depletion on the pulmonary functions was evaluated. In the control group LDF was not used. Sequestration of leukocytes in the lung and the ratio of dry/wet weight of the lung were measured. Oxygen free radicals in lung tissue was determined By ESR, and the levels of serum MDA, as well as ultrastructural changes in the lung tissue were also examined. The filtration efficiency rate for white blood cells was 0.93±0.05( vs before the filtration P<0.01), the ratio of dry/wet weight was 0.258±0.011 in control group and 0.612±0.023 in experimental group(P<0.01),respectively.It was found that oxygen free radical levels were lower in the experimental group than control group(P<0.01) consistantly. MDA level increased from 0.574±0.051nmol/mg before bypass to 1.371±0.078nmol/mg(P<0.01) after bypass,while it was 2.089±0.108nmol/mg in control group; it was 0.523±0.048nmol/mg before bypass and 0.587±0.056nmol/mg 60min after bypass in experimental group. The difference was significant(P<001). Electronmicroscopic studies demonstrated that lung tissue was well arranged with the clearly demonstrated myomeres, and the mitochondrial structures were relatively well preserved. The electron density was reduced during the reperfusion period,and it was more pronounced in the experimental group (P< 0.05). It suggested that LDF can significantly attenuate lung reperfusion injury and has protective effect on the pulmonary functions.