title: Plasma and synovial fluid endothelin-1 and nitric oxide concentrations in horses with and without joint disease.
abstract: OBJECTIVE
  To compare plasma and synovial fluid endothelin-1 (ET-1) and nitric oxide (NO) concentrations in clinically normal horses and horses with joint disease.
  
  
  METHODS
  36 horses with joint disease, and 15 horses without joint disease.
  
  
  METHODS
  Horses with joint disease were assigned to 1 of the 3 groups (ie, synovitis, degenerative joint disease [DJD], or joint sepsis groups) on the basis of findings on clinical and radiographic examination and synovial fluid analysis. Endothelin-1 and NO concentrations were measured in plasma from blood samples, collected from the jugular vein and ipsilateral cephalic or saphenous vein of the limb with an affected or unaffected joint, as well as in synovial fluid samples obtained via arthrocentesis from the involved joint.
  
  
  RESULTS
  Plasma ET-1 concentrations between affected and unaffected groups were not significantly different. Median concentration and concentration range of ET-1 in synovial fluid obtained from the joint sepsis group (35.830 pg/mL, 7926 to 86.614 pg/mL; n = 7) were significantly greater than values from the synovitis (17.531 pg/mL, 0.01 to 46.908 pg/mL; 18), DJD (22.858 pg/mL, 0.01 to 49.990 pg/mL; 10), and unaffected (10.547 pg/mL, 0.01 to 35.927 pg/mL; 10) groups. Plasma and synovial fluid NO concentrations between affected and unaffected groups were not significantly different.
  
  
  CONCLUSIONS
  Endothelin-1 is locally synthesized in the joints of horses with various types of joint disease. Synovial fluid concentrations of ET-1 varied among horses with joint disease, with concentrations significantly higher in the synovial fluid of horses with joint sepsis. These results indicate that ET-1 may play a role in the pathophysiologic mechanism of joint disease in horses.
authors.affiliation: Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: de la Calle
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Burba
authors.forename: Chidambaram M
authors.initials: CM
authors.lastname: Ramaswamy
authors.forename: Giselle
authors.initials: G
authors.lastname: Hosgood
authors.forename: Jamil
authors.initials: J
authors.lastname: Williams
authors.forename: Casey
authors.initials: C
authors.lastname: LeBlanc
authors.forename: Rustin M
authors.initials: RM
authors.lastname: Moore
mesh_terms: D000818:Animals; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000097:blood; D005260:Female; D006734:Horse Diseases / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D006736:Horses; D007592:Joint Diseases / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D007794:Lameness, Animal / Q000473:pathology; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000097:blood; D018709:Statistics, Nonparametric; D013582:Synovial Fluid / Q000378:metabolism*
chemical_list: D019332:Endothelin-1; D009569:Nitric Oxide