title: Intra-abdominal hyaluronan concentration in peritoneal fluid of horses with sudden signs of severe abdominal pain.
abstract: OBJECTIVE
  To determine hyaluronan concentrations in peritoneal fluid from healthy horses and horses with sudden signs of severe abdominal pain and to identify the cellular sources of hyaluronan within the peritoneal cavity.
  
  
  METHODS
  7 client-owned horses that were evaluated for sudden signs of severe abdominal pain, 6 healthy teaching horses, and 13 euthanized horses (11 with no abdominal disease and 2 that had undergone abdominal surgery 2 weeks previously for a different study).
  
  
  METHODS
  Abdominal fluid was collected from the client-owned and teaching horses. Hyaluronan concentrations were determined with an ELISA. Equine mesothelial cells were aseptically harvested from euthanized horses immediately after euthanasia, cultured, and processed for western blot immunoassays to detect expression of the following mesothelial cell markers: cytokeratins 8 and 18, vimentin, calretinin, mesothelin, and CD44. A reverse transcriptase-PCR assay was used to detect genetic expression of hyaluronan synthase-2 (HAS-2) from cultured and native equine tissue.
  
  
  RESULTS
  The mean ± SD abdominal hyaluronan concentration in peritoneal fluid from horses with signs of abdominal pain (1,203.3 ± 46.3 ng/mL) was significantly greater than that in healthy horses (228.4 ± 167.3 ng/mL). Harvested cells were maintained, and immunoblotting analyses confirmed expression of the mesothelial markers. Gene expression of HAS-2 from cultured mesothelial cells and fibroblasts was confirmed.
  
  
  CONCLUSIONS
  Peritoneal hyaluronan concentration was much higher in horses with severe abdominal pain than in healthy horses. Cultured equine mesothelial cells and fibroblasts can produce hyaluronan through HAS-2. Future investigation should focus on establishing the effect of exogenous hyaluronan administration on mesothelial cell function in horses with abdominal disease.
authors: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA. lillich@vet.k-state.edu
authors: James D
authors: JD
authors: Lillich
authors: Wendy
authors: W
authors: Ray-Miller
authors: Kristopher S
authors: KS
authors: Silver
authors: Elizabeth G
authors: EG
authors: Davis
authors: Bruce D
authors: BD
authors: Schultz
mesh_terms: D015746:Abdominal Pain / Q000378:metabolism / Q000662:veterinary*; D000818:Animals; D001202:Ascitic Fluid / Q000737:chemistry* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis* / Q000097:blood; D015153:Blotting, Western / Q000662:veterinary; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D006820:Hyaluronic Acid / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D010529:Peritoneal Cavity / Q000166:cytology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D015415:Biomarkers; D006820:Hyaluronic Acid; D014453:Glucuronosyltransferase