L-精氨酸在供肺离体保存中的作用

Effects of L-Arg on isolated lung preservation

目的 :探讨NO前体L 精氨酸 (L Arg)在供肺离体保存中的作用及可能机制 .方法 :将实验犬 1 0只随机分为 2组 ,每组 5只 ,对照组以 4℃euro collins(EC)液灌注及保存供肺 ,实验组以 4℃含L Arg(2 g/L)的EC液灌注及保存供肺 .分别于肺离体低温保存 30 ,6 0 ,1 2 0 ,1 80和 2 4 0min后取材 ,测定不同时间点NO、超氧化物歧化酶 (SOD)和丙二醛 (MDA)含量变化及 2 4 0min肺组织的湿干质量比 (W/D)和超微结构的改变 .结果 :两组在不同时间点NO ,SOD ,MDA的含量和W/D有显著性差异 (P <0 .0 5 ,P <0 .0 1 ) ;实验组肺组织中NO及SOD含量明显增高 ,MDA含量显著降低 .随着时间的延长 ,NO ,SOD均有下降趋势 ,但实验组下降幅度较对照组小 .MDA均轻度上升 ,但实验组上升幅度较对照组小 .W /D测定及光镜检查发现 ,实验组损伤明显轻于对照组 (P <0 .0 5 ) .结论 :在EC液中加入L Arg用于离体肺的灌注和保存 ,能明显减轻供肺损伤 ,其机制可能与NO生成增加。

AIM: To investigate the effects of L Arg on the preservation of isolated donor lung and underlying mechanisms. METHODS: Ten dogs were randomly divided into 2 groups. In the control group, the isolated donor lungs were flushed with and preserved in cold euro collins solution (EC) at 4℃. In the experimental group, the isolated donor lungs were flushed with and preserved in cold EC added with 2 g/L L Arg at 4℃. After preserved for 30, 60, 120, 180, 240 min respectively, the tissue samples of the donor lung were taken for the measurement of nitric oxide (NO), superoxide dismutase (SOD) and malondialdehyde (MDA) contents. In addition, the wet to dry weight ratio (W/D) and histological changes were also observed at 240 min. RESULTS: There were significant differences in NO, SOD, MDA contents and W/D at any appointed time points ( P <0.05, P <0.01). The NO and SOD contents of the experiment group were significantly higher than those of the control group. But the MDA content was lower in the experimental group than that in the control group. With the prolongation of preserving duration, the NO and SOD contents tended to drop more prominent in the experimental group while MDA level tended to rise. The W/D determination and light microscopy revealed that the donor lungs in the control group were more seriously damaged. CONCLUSION: L Arg added in EC has significant protective effects on isolated donor lungs, which may be due to the increased NO production and changes of the balance between clearout and production of oxygen free radicals.