title: In vitro characterization of chondrocytes isolated from naturally occurring osteochondrosis lesions of the humeral head of dogs.
abstract: OBJECTIVE
  To characterize chondrocytes from naturally occurring osteochondrosis (OC) lesions of the humeral head of dogs.
  
  
  METHODS
  15 cartilage specimens from 13 client-owned dogs with humeral head OC and 10 specimens from the humeral head of healthy dogs (controls).
  
  
  METHODS
  Chondrocytes were isolated and cultured in a 3-dimensional system. On days 7, 10, 15, 20, and 25, glycosaminoglycan and hydroxyproline content and cytologic characteristics were evaluated. Expression of collagen types I, II, and X was assessed by use of immunohistochemistry.
  
  
  RESULTS
  Chondrocytes from OC lesions were less viable, compared with control chondrocytes. Glycosaminoglycan content in the OC group was significantly less than in the control group on all days except day 20. Hydroxyproline content was also significantly less in the OC group on days 10, 20, and 25. Expression of collagen type II was significantly less in the OC group, compared with the control group on all days, whereas expression of collagen type I was significantly greater in the OC group on days 20 and 25. Expression of collagen type X was significantly less in the OC group on all days except day 25.
  
  
  CONCLUSIONS
  Chondrocytes from naturally occurring OC lesions of the humeral head of dogs cultured in a 3-dimensional system were less viable and less capable of producing appropriate extracellular matrix molecules than chondrocytes from unaffected dogs. Alterations in the synthetic capabilities of chondrocytes from OC-affected cartilage may be a cause or an effect of the disease process.
authors.affiliation: Comparative Orthopaedic Laboratory, University of Missouri, Columbia 65211, USA.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kuroki
authors.forename: James L
authors.initials: JL
authors.lastname: Cook
authors.forename: James L
authors.initials: JL
authors.lastname: Tomlinson
authors.forename: John M
authors.initials: JM
authors.lastname: Kreeger
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019902:Chondrocytes / Q000473:pathology*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis; D006811:Humerus / Q000473:pathology*; D006909:Hydroxyproline / Q000032:analysis; D008297:Male; D010007:Osteochondritis / Q000473:pathology / Q000662:veterinary*
chemical_list: D006025:Glycosaminoglycans; D006909:Hydroxyproline