title: Induction of IL-6 within the rodent intestinal muscularis after intestinal surgical stress.
abstract: 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.
authors.affiliation: Department of Surgery, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Wehner
authors.forename: Nicolas T
authors.initials: NT
authors.lastname: Schwarz
authors.forename: Ricarda
authors.initials: R
authors.lastname: Hundsdoerfer
authors.forename: Christian
authors.initials: C
authors.lastname: Hierholzer
authors.forename: David J
authors.initials: DJ
authors.lastname: Tweardy
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Billiar
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Bauer
authors.forename: Joerg C
authors.initials: JC
authors.lastname: Kalff
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D015850:Interleukin-6 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D007421:Intestine, Small / Q000276:immunology* / Q000601:surgery*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D023421:Models, Animal; D009130:Muscle, Smooth / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011912:Rats, Inbred ACI; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D015850:Interleukin-6; D012333:RNA, Messenger