title: Gut luminal endotoxin reduces ischemia-reperfusion injury of the small gut in germ-free pigs.
abstract: Translocation of luminal bacteria and their products through the intestinal mucosa during ischemia-reperfusion (I/R) may modify I/R injury. To test this hypothesis, 16 germ-free pigs were studied prior to and after clamping the superior mesenteric artery (SMA) and 12 pigs served as controls. Nine pigs in the I/R and 5 in the control group received endotoxin intragastrically, 60 min before baseline. Gut absorption of an inert indicator (polyethyleneglycol [PEG] 3350), gut intraluminal PCO2 (tonometry), and systemic and regional hemodynamic variables were measured up to 4 h after baseline. Gut blood flow was stopped during clamping, some reactive hyperemia occurred up to 30 min after declamping in the I/R groups, independently of prior endotoxin administration. Gut intraluminal-arterial PCO2 gradients were elevated in I/R versus control groups during I and for some time during R, prior endotoxin had no effect. However, in controls without and with luminal endotoxin, PEG urinary excretion, as percentage of the dose administered, was 0.12 +/- 0.12 and 0.17 +/- 0.07, respectively, while it measured 1.82 +/- 0.70 in the I/R group and 0.55 +/- 0.37% in the I/R and endotoxin groups, respectively (P< 0.001). The data suggest that gut luminal endotoxin ameliorates I/R injury of the gut wall in germ-free pigs, without altering changes in gut perfusion adequacy and systemic hemodynamics.
authors.affiliation: Medical Intensive Care Unit, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: van der Hoven
authors.forename: M
authors.initials: M
authors.lastname: Nabuurs
authors.forename: L A
authors.initials: LA
authors.lastname: van Leengoed
authors.forename: A B
authors.initials: AB
authors.lastname: Groeneveld
authors.forename: L G
authors.initials: LG
authors.lastname: Thijs
mesh_terms: D000818:Animals; D004731:Endotoxins / Q000502:physiology*; D005856:Germ-Free Life; D006439:Hemodynamics; D007422:Intestines / Q000098:blood supply* / Q000503:physiopathology; D015427:Reperfusion Injury / Q000503:physiopathology*; D013552:Swine
chemical_list: D004731:Endotoxins