肝脏肿瘤缺血再灌注损伤后超氧化物歧化酶和丙二醛的改变及意义

Changes and implications of SOD and MDA after ischemia-reperfusion injury of hepatic neoplastic tissue

目的 探讨缺血再灌注对肿瘤组织的影响及其意义。方法 通过超声引导将VX2肿瘤组织混悬液穿刺注射到新西兰兔肝脏左中叶 ,建立肝脏肿瘤模型 ,用无损伤血管钳阻断肿瘤所在肝叶的肝动脉分支 60min后去除血管阻断恢复血流 ,随机将模型动物分为缺血再灌注前 (对照 )、缺血再灌注后 0min、1h、1d、3d、1周 6个时间组 ,取肝脏组织和肿瘤组织 ,分别测定超氧化物歧化酶 (SOD)和丙二醛 (MDA)的含量。结果 肝脏组织中的SOD含量于缺血再灌注后迅速下降 ,至 0min达最低点 ,随后有所升高 ,至 7d时仍明显低于缺血再灌注前水平 ,各组与对照组对比差异显著 (P <0 .0 0 1) ,而肿瘤组织的SOD含量变化趋势除了 1h达最低点外 ,其余皆与肝脏组织相似 ,各组与对照组对比差异显著 (P<0 .0 0 1) ;肝脏组织的MDA含量于 0min时升至最高 ,随后开始下降 ,至 7d时仍高于缺血再灌注前水平 ,各组与对照组对比差异显著 (P <0 .0 0 1) ,而肿瘤组织的MDA含量于 1h降至最低 ,随后有所升高 ,但至 7d时仍明显低于缺血再灌注前水平 ,各组与对照组比较差异显著 (P <0 .0 0 1)。结论 肿瘤组织缺血再灌注后氧自由基的生成和损伤较正常肝脏组织明显。

Objective To explore the influence of ischemia reperfusion on hepatic neoplastic tissue and its implications.Methods The hepatic neoplasm animal model was established by ultrasound-guided implantation of VX 2 tumor constitutional mass into the left-middle lobe of rabbits' liver. Ischemia was induced by non-traumatic vascular clamp blocking the branches of hepatic artery supplying the left-middle lobe of liver for 60 minutes, and then released the clamp. The animal models were randomly divided into control group (before ischemia and reperfusion), and 0min, 1h, 1d, 3d and 7d groups then the normal and hepatic neoplastic tissues were taken out for determination of superoxide dismutase (SOD) and malondialdehyde (MDA) respectively.Results The SOD content of the hepatic tissue decreased rapidly to the lowest point at 0min after ischemia reperfusion and then restored gradually, but still lower than that of the control group at 7d(P<0.001 vs. the control group). The change of the SOD content of the neoplastic tissue was similar to that of the hepatic tissue, the lowest level was at 1h (P<0.001 vs. the control group). The MDA content of hepatic tissue increased to its highest level at 0min and then dropped, but remained higher than that of the control group at 7d(P<0.001 vs. the control group). The MDA content of the neoplastic tissue decreased to the lowest level at 1h and restored gradually, but also remained lower than that of the control group at 7d(P<0.001 vs. the control group).Conclusion The production and damaging effect of oxygen free raical on the neoplastic tissue are more severe than those of the normal hepatic tissue.