Bile increases lipopolysaccharide release in experimental E. coli peritonitis

Previous studies in rats showed increased mortality when bile was added to intraperitoneally injected Escherichia coli. In the present study bacterial counts and levels of lipo-polysaccharide (LPS) were determined in the peritoneal cavity and in blood 0.5, 1, 4 and 10 hours after induction of peritonitis with E. coli alone or together with bile. LPS was measured with gas chromatographic analysis of beta-hydroxymyristic acid, a characteristic component of E. coli-LPS. Bacterial counts and LPS levels in peritoneal fluid and blood rose higher in E. coli + bile peritonitis than in E. coli peritonitis. The intergroup difference in LPS levels was evident at 0.5 and 1 hour, whereas the bacterial counts began to differ at 2 hours. Presence of intraperitoneal bile in E. coli peritonitis thus produced rapid rise in LPS levels that could not be caused by bacterial numbers alone. This early load of LPS may help to explain the noxious effect of bile in E. coli peritonitis.