丙二醛、超氧化物歧化酶及内毒素在大鼠布加综合征模型肝损伤中的表达及意义

Expression and significance of malonaldehyde, superoxide dismutase and endotoxin in liver injury model of Budd-Chiari syndrome in rats

目的探讨丙二醛（MDA）、超氧化物歧化酶（SOD）及内毒素（ET）在大鼠布加综合征（BCS）肝损伤模型中的表达及意义。 方法通过部分结扎大鼠肝后段下腔静脉建立BCS动物模型。所有实验大鼠分为3组：健康对照组（12只）、模型组（48只）和假手术组（48只），模型组及假手术组又各分4个亚组（实验1、3、6、12周），每亚组12只大鼠。行DSA证实造模成功后每组随机抽取9只大鼠处死，留取血清及肝脏组织，采用双抗体夹心法检测肝匀浆及血清中MDA、SOD及ET的表达量。通过Levene法检验所测数据符合方差齐性后，以方差分析比较组内、组间的差异，采用LSD法行组内、组间两两比较，采用Pearson法行MDA、SOD及ET相关性分析。 结果模型组大鼠术后肝匀浆及血清中各时间点的MDA、SOD、ET值与对照组及假手术组中相应指标比较，差异均具有统计学意义（MDA：肝匀浆F值分别为52.906、219.016，血清分别为21.573、43.878；SOD：肝匀浆F值分别为22.927、19.317，血清分别为10.841、31.643；ET：肝匀浆F值分别为33.588、105.515，血清分别为40.832、46.323；P值均〈0.05）。模型组术后各时间点肝匀浆MDA值差异有统计学意义（F=7.716，P=0.001），血清MDA值差异无统计学意义（F=1.965，P=0.139）；模型组肝匀浆及血清SOD及ET值在术后各时间点比较，差异均有统计学意义（SOD：F值分别为17.053、7.903；ET：F值分别为19.870、39.372；P值均〈0.05），两者在肝匀浆及血清中含量均从术后1周开始逐渐上升，6周达峰值，第12周稍下降。模型组各时间点肝匀浆MDA及ET较假手术组上升值均高于血清中相应上升值。模型组肝匀浆及血清中MDA与SOD均为负相关（r分别为－0.814、－0.591，P均为0.001）、与ET均为正相关（r分别为0.761、0.422，P分别为0.004、0.001），SOD与ET均为负相关（r分别为－0.726、－0.490，P均为0.001）。 结论BCS动物模型肝脏及血清中MDA、SOD及ET等缺氧相关指标表达水平早期就有不同程度改变，随病程进展呈加重趋势；后期随侧支循环建立稍有缓解，但仍明显高于正常水平。这提示瘀血缺氧贯穿了BCS病损的整个进程，并可能是其主要因素及始动因素。

ObjectiveTo investigate the expression and significance of malonaldehyde （MDA）, superoxide dismutase （SOD） and endotoxin （ET） in liver injury model of Budd-Chiari syndrome （BCS） in rats. MethodsThe animal model of BCS was established by partially ligating the inferior vena cava of the posterior segment of liver in rats. The experimental animals were divided into three groups： control group （12 rats）, model group （48 rats） and sham operation group （48 rats）. The model group and sham operation group were divided into four subgroups （1, 3, 6, 12 weeks） of 12 rats each. After the success of modeling, being confirmed by digital subtraction angiography （DSA）, nine rats in each group were sacrificed at random respectively, where their serums and liver tissues was collected. The levels of MDA, SOD and ET in both liver homogenate and serum were examined respectively. ANOVA was used to compare the total difference between groups and within group of each measurement data. The LSD method was used to do multiple comparison within group and between groups. Pearson method was used to do correlation analysis of hypoxia markers. ResultsThe levels of MDA, SOD and ET in liver homogenate and serum at different time points in model group were significantly different from those in control group and sham operation group （MDA： liver homogenate （F=52.906, 219.016）, serum （F=21.573, 43.878）;SOD： liver homogenate （F=22.927, 19.317）, serum （F=10.841, 31.643）;ET： liver homogenate （F= 33.588, 105.515）, serum （F= 40.832, 46.323）;P〈0.05）. The total difference of the MDA level in serum at each time point after the operation was not statistically significant in model group（F=1.965, P=0.139）, but that of liver homogenate in the model group was statistically significant （F=7.716, P=0.001）. The SOD and ET levels in both liver homogenate and serum of model group were compared within groups at different time points after operation respectively, and the overall difference was statistically significant （SOD： F=17.053, 7.903;ET： F=19.870, 39.372;P〈0.05）. The time-varying curves of MDA and ET in liver homogenate and serum in model group were similar, which both increased from 1 week after operation,peaked at 6th week and slightly decreased at 12th week. The increase levels of MDA and ET in liver homogenate were significantly higher than those in serum. There was a negative correlation between MDA and SOD in liver homogenate and serum （r=-0.814,-0.591;P=0.001, 0.001）, a positive correlation between MDA and ET （r=0.761, 0.422;P=0.004, 0.001）, and a negative correlation between SOD and ET （r=-0.726,-0.490;P=0.001, 0.001）. ConclusionsThe levels of hypoxia related markers, such as MDA, SOD and ET in liver and serum of BCS animal model, change to varying degrees in the early stage, and will be aggravated as the disease continues to advance. In the later stage, with the establishment of collateral circulation, hypoxia will be slightly eased, but is still significantly higher than normal, which indicates that congestion and hypoxia run through the whole process of BCS, and could be the key and initiating factors.