Lipid peroxidation and liver damage in double and simple common bile duct ligation models in male Sprague-Dawley rats

Aims: Bacterial translocation, defined as the presence of living bacteria or bacterial fragments in both mesenteric lymph nodes or systemic circulation, can cause a severe inflammatory reaction in patients with cirrhosis. This study aimed to compare lipid peroxidation associated with liver damage in different experimental models of bile duct ligation: proximal double ligation and transection versus proximal simple ligation versus sham. Materials and methods: Sixty-two male rats underwent one of three bile duct surgical interventions: proximal double ligation and transection (n = 22); proximal simple ligation (n = 19); or sham operation (n = 21). We performed microbiological culture of mesenteric lymph nodes; portal and cava blood, spleen and liver cultures; and histological analysis of liver parenchyma. Samples of blood and liver were obtained at laparotomy for malondialdehyde quantification. Key findings: Serum malondialdehyde levels were significantly higher in simple ligature animals (3.7 nmol/mg, standard deviation [SD] 2.1) compared to controls (1.6 nmol/mg SD 0.5; p = 0.001) or double ligature (0.3 nmol/mg SD 0.3; p = 0.001). Liver malondialdehyde levels were significantly higher in animals subjected to double ligation vs controls (9.0 nmol/mg SD 2.8 vs. 1.7 nmol/mg SD 1.0; p = 0.0007) and simple ligature (2.9 nmol/mg SD 2.0; p = 0.0001). Overall incidence of bacterial translocation was similar in simple and double ligatures (22.2 % and 21 % respectively), and significantly higher than in controls. Significance: the type of bile duct ligation influences the type and localization of lipid peroxidation, but does not influence the development of bacterial translocation.