title: Post-ischaemic restituted intestinal mucosa is more resistant to further ischaemia than normal mucosa in the pig.
abstract: OBJECTIVE
  Ischaemic preconditioning may protect the intestine from subsequent prolonged ischaemia. This study evaluates whether a much longer initial ischaemia, encountered clinically, may modify intestinal resistance to further ischaemia in a pig model.
  
  
  METHODS
  After cross-clamping of the superior mesenteric artery for 1 h, the intestine was either reperfused for 8 h or a second cross-clamping for 1 h was performed at 4 h of reperfusion. Based on microarray analysis of intestinal samples at 1, 4 and 8 h of reperfusion, mRNA of selected genes was measured with QRT-PCR.
  
  
  RESULTS
  The first ischaemic period caused exfoliation of surface epithelial cells from the basement membrane comprising about 90 % of the villi tips, a marked increase in permeability and depletion of ATP. The second ischaemic challenge caused about 30 % less denudation of the basement membrane (p = 0.008), no increase in permeability (p = 0.008) and less depletion of ATP (p = 0.039). mRNAs for superoxide dismutase 2, heat shock proteins and signal transducer and activator of transcription 3, which may protect against ischaemia/reperfusion injury, were up-regulated throughout the reperfusion period. mRNAs for matrix metalloproteinase 1, connexin 43 and peripheral myelin 22, which may be associated with cell migration or tight junctions, showed a particular up-regulation at 4 h of reperfusion.
  
  
  CONCLUSIONS
  One hour of initial ischaemia followed by 4 h of reperfusion is associated with increased intestinal resistance to further ischaemia. The differential regulation of genes identified in this study provides working hypotheses for mechanisms behind this observation.
authors.affiliation: Department of Surgery, St. Olav University Hospital, NO-7006 Trondheim, Norway. ingebjorg.juel@ntnu.no
authors.forename: Ingebjørg S
authors.initials: IS
authors.lastname: Juel
authors.forename: Erik
authors.initials: E
authors.lastname: Solligård
authors.forename: Kåre E
authors.initials: KE
authors.lastname: Tvedt
authors.forename: Eirik
authors.initials: E
authors.lastname: Skogvoll
authors.forename: Per
authors.initials: P
authors.lastname: Jynge
authors.forename: Vidar
authors.initials: V
authors.lastname: Beisvag
authors.forename: Sten Even
authors.initials: SE
authors.lastname: Erlandsen
authors.forename: Arne K
authors.initials: AK
authors.lastname: Sandvik
authors.forename: Petter
authors.initials: P
authors.lastname: Aadahl
authors.forename: Jon Erik
authors.initials: JE
authors.lastname: Grønbech
mesh_terms: D000818:Animals; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000098:blood supply / Q000473:pathology*; D007511:Ischemia / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D012039:Regional Blood Flow