Exacerbation of alcoholic liver injury by enteral endotoxin in rats

Authors

  • Philippe Mathurin,

    1. Departments of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA
    Search for more papers by this author
  • Qing-Gao Deng,

    1. Departments of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA
    Search for more papers by this author
  • Ali Keshavarzian,

    1. Division of Digestive Diseases, Rush Presbyterian St. Luke's Medical Center, Chicago, IL
    Search for more papers by this author
  • Sandeep Choudhary,

    1. Division of Digestive Diseases, Rush Presbyterian St. Luke's Medical Center, Chicago, IL
    Search for more papers by this author
  • Earle W. Holmes,

    1. Department of Pathology, Loyola University Stritch School of Medicine, Chicago, IL
    Search for more papers by this author
  • Hidekazu Tsukamoto

    Corresponding author
    1. Departments of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA
    2. Departments of Pathology, University of Southern California Keck School of Medicine, Los Angeles, CA
    3. Greater Los Angeles VA Health Care System, Sepulveda, CA
    • University of Southern California, Keck School of Medicine, 1333 San Pablo Street, MMR-414, Los Angeles, CA 90033. fax: 323-442-3126
    Search for more papers by this author

Abstract

Increased gut permeability (leaky gut) and endotoxin-mediated Kupffer cell activation are proposed as the mechanisms of alcoholic liver injury. Although ethanol feeding is shown to sensitize the liver for injury induced by parental administration of lipopolysaccharide (LPS), how enteral LPS loading affects alcoholic liver injury is yet to be tested. The present study provides direct evidence for enhanced entrance to portal circulation of LPS enterally administered to the intragastric ethanol infusion model. Portal and systemic blood endotoxin levels increased to 43.0 ± 4.1 and 6.2 ± 4.3 pg/mL at 2 hours following enteral LPS administration (5 mg/kg) in alcohol-fed animals, while no such increases were observed in pair-fed controls. However, endotoxin levels in systemic blood of alcohol-fed rats were reduced to 0 to 1.5 pg/mL 16 hours after LPS administration. Weekly enteral administration of LPS to the model for 9 weeks exacerbated an increase in plasma alanine transaminase (ALT) levels (227 ± 75 vs. 140 ± 70; P < .01), mononuclear infiltration (25 ± 22 vs. 6.4 ± 4.4/10 mm2; P = .02), sinusoidal congestion, and spotty necrosis, and induced diffuse coagulative necrosis and centrilobular fibrosis in some animals. Reverse-transcription polymerase chain reaction (RT-PCR) analysis confirmed the LPS effect at the tissue level by demonstrating accentuated induction of tumor necrosis factor α (TNF-α) and Cox-2 mRNA. In conclusion, enteral LPS administration potentiates alcoholic liver necrosis, inflammation, and fibrosis despite efficient endotoxin clearance by the liver and mild systemic endotoxemia that occurs episodically following enteral LPS challenge.

Ancillary