title: In vitro and in vivo responses of mucosa from the large colon of horses to ischemia and reperfusion.
abstract: OBJECTIVE
  To induce ischemia and reperfusion injury in the large colon mucosa of horses in vivo and evaluate the recovery and effects of components of an organ transplant solution on mucosal recovery in vitro.
  
  
  METHODS
  6 healthy horses.
  
  
  METHODS
  Horses were anesthetized, and ischemia was induced for 60 minutes in the pelvic flexure, which was followed by reperfusion for 240 minutes. Ischemic (n = 4 horses), reperfused (6), and adjacent control (6) colonic mucosae were isolated for in vitro testing and histologic examinations. Tissues were mounted in Ussing chambers with plain Krebs Ringer bicarbonate (KRB), KRB with N-acetylcysteine (NAC), or KRB with a modified organ transplant solution (MOTS). Transepithelial electrical resistance (TER) and mannitol flux were used to assess mucosal integrity. Data were analyzed by use of ANOVA and Kruskal-Wallis tests.
  
  
  RESULTS
  The TER in reperfused tissues was similar to the TER in control tissues and greater than the TER in ischemic tissues, which was consistent with morphological evidence of recovery in reperfused tissues. Mannitol flux was greater in ischemic tissues than in reperfused tissues. The TER and mannitol flux were not significantly affected by incubation of mucosa with NAC or MOTS.
  
  
  CONCLUSIONS
  Ischemia induced during the brief period allowed rapid mucosal repair and complete recovery of tissue barrier properties during reperfusion. Therefore, reperfusion injury was not observed for this method of ischemic damage in equine colonic mucosa.
authors: Island Whirl Equine Colic Research Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA. sarahgraham@ufl.edu
authors: A Sarah
authors: AS
authors: Graham
authors: Astrid
authors: A
authors: Grosche
authors: Alison J
authors: AJ
authors: Morton
authors: Maximilian M R
authors: MM
authors: Polyak
authors: David E
authors: DE
authors: Freeman
mesh_terms: D000704:Analysis of Variance; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000818:Animals; D003106:Colon / Q000098:blood supply / Q000473:pathology*; D003975:Diazepam / Q000008:administration & dosage; D017097:Electric Impedance; D006734:Horse Diseases / Q000139:chemically induced / Q000473:pathology*; D006736:Horses; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D007413:Intestinal Mucosa / Q000473:pathology; D007511:Ischemia / Q000473:pathology / Q000662:veterinary*; D007649:Ketamine / Q000008:administration & dosage; D008353:Mannitol / Q000378:metabolism; D015427:Reperfusion Injury / Q000473:pathology / Q000662:veterinary*; D018709:Statistics, Nonparametric; D014991:Xylazine / Q000008:administration & dosage
chemical_list: D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D014991:Xylazine; D008353:Mannitol; D007649:Ketamine; D003975:Diazepam