缺血预处理对肝脏缺血再灌注所致急性肺损伤的保护作用

目的:观察全肝缺血再灌注后所致急性肺损伤的发病机制及缺血顸处理的保护作用.方法:通过脾静脉-股静脉转流建立大鼠全肝缺血再灌注模型.18只大鼠随机分3组,全肝缺血40 min再灌注3 h组(IR组);缺血预处理组(IP组),阻断肝脏血流5 min再灌注5 min后,再行全肝缺血40 mjn再灌注3 b;对照组(C组)仅行麻醉及假手术.3 h后检测各组肺泡灌洗液中总蛋白的含量、肺组织含水量以及髓过氧化物酶(MPO)含量和组织及血中丙二醛(MDA)含量.结果:与C组比较,IR组肺泡灌洗液总蛋白含量和肺组织含水量明显升高,而IP组增高不明显.IR组肺组织MPO和MDA及血清中MDA含量明显高于对照组,而预处理可以减少MPO和MDA的升高.结论:肝脏缺血再灌注通过中性粒细胞浸润和氧化应激反应导致急性肺损伤.缺血预处理可以减少粒细胞的浸润,增加抗氧化的能力,减轻肺损伤.

Protective effect of ischemia preconditioning on acute lung injury after hepatic ischemia/reperfusion

Objective: To investigate the mechanism of acute lung injury after hepatic ischemia/ reperfusion and the protective effect of ischemia preconditioning. Methods: Eighteen healthy Wistar rats weighting 240 to 280 g were randomly divided into 3 groups (6 in each group). Group I/R: the hepatic pedicle was clamped for 40 minutes with portal bypass and then opened for reperfusion which lasted for 3 hours. Group IP: the hepatic pedicle was clamped for 5 minutes and untied for 5 minutes and then ischemia reperfusion was produced as Group I/R. Group C: the hepatic pedicle was only exposed for 40 minutes. In addition to broncho-alveolar lavage fluid protein (BALFP) content, water content of lung tissue, and malondialdehyde (MDA) in serum and lung tissue were measured. The concentration of myeloperoxidase(MPO) in lung tissue was also examined. Results: Compared with group C, the BALFP and water content were significantly increased in Group I/R, but which were unmarkably increased in group IP. The content of MPO and MDA in lung tissue and serum MDA in group I/R were higher than those in group C and group IP. Preconditioning might decrease the improvement of MPO and MDA. Conclusion: Acute lung injury after hepatic ischemia/ reperfusion is mainly induced by the oxidant stress and neutrophil infiltration in lung tissues. Ischemia preconditioning may have effects of antioxidation and decrease neutrophil infiltration which attenuate lung injury induced by hepatic ischemia/ reperfusion.