Induction of IL-6 within the rodent intestinal muscularis after intestinal surgical stress

Surgery. 2005 Apr;137(4):436-46. doi: 10.1016/j.surg.2004.11.003.


Background: Postoperative ileus is a poorly understood surgical problem characterized by leukocyte extravasation into the intestinal muscularis and suppression in muscle function. The study objective was to delineate a mechanistic inflammatory cascade initiated by intestinal manipulation.

Methods: ACI and Sprague-Dawley rats, and IL-6 +/+ and IL-6 -/- mice were subjected to intestinal manipulation. One group of rats received adhesion molecule-blocking antibodies (1A29 and WT.3) before intestinal manipulation. Interleukin-6 (IL-6) messenger RNA (mRNA) levels and electrophoretic mobility shift assay for signal transducers and activators of transcription (STAT) activation were measured in tissue extracts. IL-6 protein levels were assessed by immunohistochemistry and enzyme-linked immunosorbent assay.

Results: IL-6 mRNA from muscularis extracts demonstrated a significant induction after intestinal manipulation. No IL-6 induction was observed in mucosal extracts. Adhesion molecule blockade resulted in a marked decrease of cellular infiltration but did not change IL-6 mRNA expression in muscularis extracts. Resident macrophages in the muscularis stained for IL-6 by immunohistochemistry after intestinal manipulation. The isolated manipulated muscularis demonstrated a significant increase in IL-6 release. Electrophoretic mobility shift assay of manipulated muscularis showed a marked increase in IL-6-dependent Stat3 activation.

Conclusions: This study demonstrates that manipulation of the small bowel during an abdominal operation initiates downstream induction, translation, release, and functional activity of IL-6 within the muscularis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers
  • Interleukin-6 / deficiency
  • Interleukin-6 / genetics
  • Interleukin-6 / physiology*
  • Intestine, Small / immunology*
  • Intestine, Small / surgery*
  • Male
  • Mice
  • Mice, Inbred Strains
  • Mice, Knockout
  • Models, Animal
  • Muscle, Smooth / immunology*
  • RNA, Messenger / genetics
  • Rats
  • Rats, Inbred ACI
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction


  • DNA Primers
  • Interleukin-6
  • RNA, Messenger