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

Abstract

Objective To 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. Methods The 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. Results The 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). Conclusions The 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. Key words: Anoxia; Endotoxins; Reactive oxygen species; Budd-Chiari syndrome