Endotoxin priming and liver damage by experimental duodenal obstruction in the rat

To verify whether endotoxin (LPS) might act as a priming cofactor of liver injury caused by obstructing the duodenum, four groups of male Wistar rats were studied. The first two groups comprised rats in which a closed duodenal loop (CDL) was created: CDL, n = 6 and CDL + LPS, n = 7; the next two groups comprised sham-operated animals: Sham n = 6 and Sham + LPS, n = 6. LPS, 400 μg/kg bodyweight, was administered i.p. to the rats belonging to groups CDL + LPS and Sham + LPS, 24 h before laparotomy. Twenty-four hours after laparotomy the animals were killed. Damage to bile ducts, extent and grading of coagulative and lytic spotty necrosis in liver tissue were evaluated morphologically. Coagulative necrosis was severe in four of seven rats of the group CDL + LPS, mild in six of six rats of group CDL, and absent in four of six and five of six rats of groups Sham and Sham + LPS (χ² 32.8, P = 0.0001). The animals of group CDL + LPS had more frequently diffuse lytic spotty necrosis than the animals in the three other groups (χ² 9.57 P < 0.01). The results of our study indicate that, in rodents subjected to a closed duodenal loop, priming with LPS exacerbates liver injury due to cholate stasis.