title: Laminar inflammatory gene expression in the carbohydrate overload model of equine laminitis.
abstract: BACKGROUND
  There is a need to assess the laminar inflammatory response in a laminitis model that more closely resembles clinical cases of sepsis-related laminitis than the black walnut extract (BWE) model.
  
  
  OBJECTIVE
  To determine if a similar pattern of laminar inflammation, characterised by proinflammatory cytokine expression, occurs in the CHO model of laminitis as has been previously reported for the BWE model.
  
  
  METHODS
  Sixteen horses administered 17.6 g of starch (85% corn starch/15% wood flour)/kg bwt via nasogastric (NG) tube were anaesthetised either after developing a temperature>38.9°C (DEV group, n=8) or at onset of Obel grade 1 lameness (OG1 group, n=8). Control horses (CON group, n=8) were anaesthetised 24 h after NG administration of 6 l of deionised water. Laminar tissue was collected from horses while under anaesthesia, followed by humane euthanasia. Real time-quantitative PCR was used to assess laminar mRNA concentrations of genes involved in inflammatory signalling.
  
  
  RESULTS
  Increased mRNA concentrations (P<0.05) for IL-1β, IL-6, IL-12p35, COX-2, E-selectin and ICAM-1 were present in laminae from horses with OG1 lameness but not at the DEV time, when compared to the CON horses. No differences between the groups were found for IL-2, IL-4, IL-10, TNF-α, IFN-γ or COX-1 at either the DEV or OG1 time points.
  
  
  CONCLUSIONS
  There was a notable difference in the temporal pattern of inflammatory events between the BWE and CHO models, with the majority of laminar inflammatory events appearing to occur at or near the onset of lameness in the CHO model, whereas many of these events peak earlier in the developmental stages in the BWE model. This suggests that, in addition to circulating inflammatory molecules, there may be a local phenomenon in the CHO model resulting in the simultaneous onset of multiple laminar events including endothelial activation, leucocyte emigration and proinflammatory cytokine expression.
  
  
  CONCLUSIONS
  The similar (although somewhat delayed) inflammatory response in the CHO model of laminitis indicates that inflammatory signalling is a consistent entity in the pathophysiology of laminitis.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, OH, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Leise
authors.forename: R R
authors.initials: RR
authors.lastname: Faleiros
authors.forename: M
authors.initials: M
authors.lastname: Watts
authors.forename: P J
authors.initials: PJ
authors.lastname: Johnson
authors.forename: S J
authors.initials: SJ
authors.lastname: Black
authors.forename: J K
authors.initials: JK
authors.lastname: Belknap
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000633:toxicity*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D005534:Foot Diseases / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006724:Hoof and Claw / Q000378:metabolism*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D007249:Inflammation / Q000378:metabolism / Q000662:veterinary*; D016133:Polymerase Chain Reaction
chemical_list: D002241:Carbohydrates; D016207:Cytokines