Changes in sulfation patterns of chondroitin sulfate in equine articular cartilage and synovial fluid in response to aging and osteoarthritis
Brown, M.P.; West, L.A.; Merritt, K.A.; Plaas, A.H.
American Journal of Veterinary Research 59(6): 786-791
1998
ISSN/ISBN: 0002-9645 PMID: 9622753 Document Number: 487982
Carpal articular cartilage and synovial fluid were obtained from cadavers of 44 horses with healthy joints and from 16 Thoroughbred racehorses during routine arthroscopic surgery for removal of osteochondral fragments and degenerative cartilage from the middle carpal and antebrachial joints. Specimens were obtained from the following age groups: fetus, <2-week-old, 2- to 8-week-old, 2- to 6-month-old, 6- to 12-month-old, 1- to 2-year-old, 2- to 4-year-old, 4- to 10-year-old and >10-year-old. Chondroitin sulfate (CS) disaccharides (unsulfated disaccharide Delta Di0S and monosulfated disaccharides Delta Di4S and Delta Di6S) were quantified by capillary zone electrophoresis. The CS non-reducing terminal residues, N-acetylgalactosamine (galNAc) or glucuronic acid adjacent to a 4-sulfated or 6-sulfated galNAc, were also quantified. In cartilage, the Delta Di6S-to- Delta Di4S ratio increased with age; in degenerative cartilage, this ratio was not significantly different from the normal value. Percentage of Delta Di0S decreased with age and was significantly higher in degenerative than in healthy cartilage. The galNAc4S and galNAc4,6S represented >=96% of the terminal residues. There was a significant decrease in 6-sulfation of the terminal residues in degenerative cartilage. 6-sulfation of internal and terminal CS residues increased with age. It is concluded that synovial fluid CS is not indicative of cartilage CS in healthy and diseased joints of horses >2-year-old and may represent turnover of proteoglycan within the matrix.