Materials. Unless otherwise noted, all chemicals were purchased from Sigma-Aldrich (St Louis, MO). The activity of LPS (Lot 075K4038, derived from Escherichia coli serotype O55:B5) was 3.3 3 10 6 endotoxin units (EU)/ mg, which was determined by a Limulus Amebocyte Lysate Kinetic-QCL kit from Cambrex Corp. (Kit 50-650U; East Rutherford, NJ). The reagents for the measurement of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT) activities were purchased from Thermo Electron Corp. (Waltham, MA). The kit for total bile acids measurement was purchased from Diazyme Laboratories (Poway, CA).