Comparison of the effects of aging and IL-6 on the hepatic inflammatory response in two models of systemic injury: scald injury versus i.p. LPS administration

Shock. 2009 Feb;31(2):178-84. doi: 10.1097/SHK.0b013e318180feb8.

Abstract

Regardless of age, a marked elevation in circulating IL-6 levels correlates with increased mortality after injury or an inflammatory challenge. We previously reported that aged IL-6 knockout mice given LPS have improved survival and reduced inflammatory response than LPS-treated aged wild type (WT) mice. Herein, we analyzed the effects of aging and IL-6 on the hepatic inflammatory response in two models of systemic injury: dorsal scald (burn) injury versus intraperitoneal LPS administration. At 24 h after burn injury, circulating alanine aminotransferase and hepatic neutrophil accumulation were comparable regardless of age or IL-6 deficiency. However, at this same time point, these indicators of liver damage, in addition to hepatic levels of KC, a neutrophil chemoattractant, were increased in aged WT mice given LPS relative to young WT mice given LPS. The hepatic injury was drastically reduced in aged IL-6 knockout mice given LPS as compared with LPS-exposed aged WT mice. Our results suggest that the nature of the insult will determine the degree of remote injury in aged animals. In addition, the role of IL-6 as a contributing factor of tissue injury may be insult specific.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aging*
  • Alanine Transaminase / blood
  • Animals
  • Burns / metabolism*
  • Female
  • Inflammation / blood*
  • Inflammation / pathology
  • Interleukin-6 / blood*
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / administration & dosage*
  • Lipopolysaccharides / toxicity
  • Liver / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Neutrophils / metabolism
  • Peroxidase / metabolism
  • Treatment Outcome

Substances

  • Interleukin-6
  • Lipopolysaccharides
  • Peroxidase
  • Alanine Transaminase