A rat model for sepsis in chronic biliary obstruction.

The effect of retrograde intrabiliary (RI) injection of E. coli was studied in Sprague-Dawley rats with and without chronic biliary obstruction. The challenge dose of E. coli was standardized by the use of frozen (-80 degrees C) aliquots of bacteria. Injection of 10(2), 10(5) or 10(8) colony-forming units (CFU), respectively, into three groups of 8 normal rats, immediately after occlusion of the common bile duct (CBD), did not kill any of the animals. In contrast, 5 of 8 animals with chronic biliary obstruction died from E. coli sepsis after RI injection of 10(2) bacteria (p less than 0.05). Furthermore, all of 4 obstructed animals died after challenge with 10(5) CFU (p less than 0.01), as compared to the 8 normal rats surviving this dose. Intraperitoneal injection of 10(5) E. coli did not kill any of 6 animals with 3 weeks biliary obstruction. It is concluded that chronic biliary obstruction and RI injection are prerequisites for the occurrence of lethal septicemia in the animals. The model might be suitable for the study of biliary sepsis in chronic biliary obstruction.