缺血预处理对无心跳供体大鼠移植肺缺血再灌注损伤的保护作用

The Protective Effects on Lung Ischemia-Reperfusion Injury by Ischemia Preconditioning in Rats Undergoing Non-heart-beating-donor Lung Transplantation

目的:研究缺血预处理(IP)对无心跳供体(NHBD)大鼠移植肺缺血再灌注损伤(IRI)的保护作用及机制。方法:将SD大鼠随机配对分成4组,分别为NHBD热缺血1h组(对照组,NHBD1h)、IP组(实验组,IP)I、P+5-羟基葵酸盐组(实验组,IP+5-HD)和IP+二甲基亚砜组(溶剂对照组,IP+DMSO),每组4对。IP方案为开胸后夹闭大鼠左侧肺门5min,开放10min,然后放血处死。热缺血1h、冷缺血4h后行左肺移植。结果:IP组移植肺再灌注10min和1h的右颈动脉血PaO2与自身术前值差优于对照组(P<0.05)。再灌注2h后,IP组左肺静脉血PaO2数值优于对照组(175.5±14.3比132.3±33.8,P<0.05)。再灌注1h和2h时,IP组的双肺顺应性优于对照组(P<0.05)。再灌注2h时,IP组以及IP+DMSO组的血清和移植肺组织丙二醛(MDA)含量、移植肺组织髓过氧化物酶(MPO)活性、肿瘤坏死因子α(TNF-α)、白介素6(IL-6)和凋亡指数显著低于NHBD1h组(P<0.05);总抗氧化能力(T-AOC)高于NHBD1h组(P<0.05);上述指标IP+5HD组与NHBD1h组比较,差异无统计学意义;各组血清TNF-α、IL-6含量之间的差异无统计学意义。光镜和电镜下观察到IP以及IP+DMSO组的细胞结构受损程度较轻,NHBD1h组以及IP+5-HD组细胞损伤较明显。结论:本大鼠模型中,单次5min缺血+10min再灌注的IP方案,对热缺血1h的大鼠NHBD移植肺IRI有较强的早期保护效应,这种保护效应与线粒体ATP敏感的钾通道开放有关。

Objective：To investigate the protective effects on lung ischemia-reperfusion injury （IRI） by ischemia preconditioning （IP） in rats undergoing non-heart-beating-donor （NHBD） lung transplantation. Methods：The NHBD model in rat orthotopic left single allograft lung transplantation was established. The warm ischemia time （WIT） was 60 rain. Thirty-two male SD rats were randomized into 16 pairs for donors and recipients, divided into 4 groups： group 1 , NHBD with 1 hour of WIT （NHBDlh, control group）; group 2, IP by one cycle of blocking the left pulmonary artery for 5 rain and then release for 10 min before killing the donor rats （IP, experimental group）; group 3, the same IP was performed, and the recipients received 5mg/kg of 5-hydroxydeeanoate （5-HD） 30 min preoperatively （IP ＋ 5 HD, experimental group）; group 4, the same IP was performed, and the recipients received 0.5 ml DMSO 30 min preoperatively （IP ＋ DMSO, DMSO control group）. The donor lungs were preserved in LPD solution at 4 C for four hours after harvesting. Then the recipient rats underwent left lung trans- plantations. Results：The PaO2 from right cervical artery after 10 minutes and 1 hour reperfusion compared with preoperative value in group 2, 4 was significant better than which in group 1, 3 （P〈0. 05）. The PaO2 from left pulmonary artery after 2 hours reperfusion in group 2 was significant better than which in group 1 （175.5 ±14.3 vs. 132.3±33.8, P〈0.05）. The pulmonary compliance after 1 hour and 2 hours reperfusion in group 2 was significant better than which in group 1 （P〈0.05）. After 2 hours reperfusion, there was significant difference in serum and pulmonary activity of malondialdehyde （MDA）, serum and pulmonary total antioxidative capabilities （T-AOC）, pulmonary activity of myeloperoxidase （MPO）, pulmonary TNF-α and IL-6, apoptotic index of alveolar cells between group 1 and group 2, 4 （P〈0.05）, whereas no significant difference was found between group 1 and group 3, no significant difference was found in serum TNF-a and IL-6 among all the groups. The morphological changes of lung injury were less severe in group 2 and group 4 compared with in group 1 and group 3. Conclu- sion：In our model, IP by one cycle of blocking the left pulmonary artery for 5 min and then release for 10 min, showed the early protective effects on IRI in NHBD donor lung with 1 hour WIT after 2 hours reperfusion. The opening of the mitochondria ATP sensitive potassium channel might play important roles.