title: Ileal mucosal oxygen consumption is decreased in endotoxemic rats but is restored toward normal by treatment with aminoguanidine.
abstract: OBJECTIVE
  We sought to test the hypothesis that ileal mucosal oxygen consumption is impaired in endotoxemic rats.
  
  
  METHODS
  Male Sprague-Dawley rats were injected intravenously with either Escherichia coli lipopolysaccharide (5 mg/kg) or a similar volume of vehicle. A segment of ileum was excised 8 hrs later, and the serosal and muscular layers of the bowel were stripped away from the mucosa. A strip of mucosa was mounted in a polarographic chamber containing air-saturated Krebs-Henseleit buffer plus 20 mM glucose, PO2 being monitored during a 10-min period. Some rats were injected intraperitoneally with the inducible nitric oxide synthase inhibitor, aminoguanidine (30 mg/kg per dose), or a similar volume of vehicle, at 1, 3 and 6 hrs after injection of lipopolysaccharide.
  
  
  RESULTS
  In an initial experiment, the rate of oxygen consumption was significantly lower for mucosal samples from endotoxemic rats as compared with control rats (0.76+/-0.11 ng-atoms vs. 1.42+/-0.22 ng-atoms of 0/min per microg dry weight, respectively; n = 8 per group; p<.05). The rate of mucosal oxygen consumption was higher in aminoguanidine-treated as compared with vehicle-treated endotoxemic rats (1.25+/-0.11 ng-atoms and 0.73+/-0.07 ng-atoms of 0/min per microg, respectively; n = 7 and n = 6, respectively; p<.05).
  
  
  CONCLUSIONS
  Endotoxemia is associated with diminished intestinal mucosal oxygen utilization due to an intrinsic acquired derangement in cellular respiration that is caused, at least in part, by an aminoguanidine-inhibitable mechanism.
authors.affiliation: Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: King
authors.forename: S
authors.initials: S
authors.lastname: Tytgat
authors.forename: R L
authors.initials: RL
authors.lastname: Delude
authors.forename: M P
authors.initials: MP
authors.lastname: Fink
mesh_terms: D000818:Animals; D019069:Cell Respiration / Q000187:drug effects; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000188:drug therapy / Q000378:metabolism* / Q000382:microbiology; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D004926:Escherichia coli; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000378:metabolism* / Q000382:microbiology; D006146:Guanidines / Q000008:administration & dosage / Q000494:pharmacology*; D007082:Ileum / Q000187:drug effects / Q000378:metabolism*; D007274:Injections, Intraperitoneal; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004791:Enzyme Inhibitors; D006146:Guanidines; D008070:Lipopolysaccharides; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D010100:Oxygen; C004479:pimagedine