title: Proteoglycan turnover during development of spontaneous osteoarthrosis in guinea pigs.
abstract: OBJECTIVE
  The study was performed to clarify the metabolic background of the variations in proteoglycan concentrations, relating to ageing and the spontaneous development of osteoarthrosis in guinea pigs.
  
  
  METHODS
  Six-, 9- and 12-month-old Hartley guinea pigs were injected intraperitoneally with Na2(35)SO4. The incorporation and degradation of various proteoglycans were analyzed in different areas of tibial articular cartilage during the development of osteoarthrosis.
  
  
  RESULTS
  Proteoglycan synthesis was most active in the uncalcified cartilage of 6-month animals and highest in the medial compartment with its presumably higher load. The breakdown of proteoglycans decreased with age. The onset of osteoarthrosis was associated with decreased synthesis of large and small proteoglycans, while the rate of degradation remained unchanged.
  
  
  CONCLUSIONS
  During onset of osteoarthrosis the synthesis of large proteoglycans gradually becomes insufficient to compensate for the simultaneous degradation. This differs from findings in more rapidly progressing, experimental secondary osteoarthrosis, where a substantial increase in the rate of degradation is more conspicuous.
authors.affiliation: Division of Orthopaedics, Huddinge University Hospital, Karolinska Institute, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Wei
authors.forename: O
authors.initials: O
authors.lastname: Svensson
authors.forename: A
authors.initials: A
authors.lastname: Hjerpe
mesh_terms: D000375:Aging / Q000378:metabolism*; D000820:Animal Diseases; D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D006168:Guinea Pigs / Q000378:metabolism*; D006614:Hindlimb; D008297:Male; D010003:Osteoarthritis / Q000378:metabolism*; D011509:Proteoglycans / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013462:Sulfur Radioisotopes
chemical_list: D011509:Proteoglycans; D013431:Sulfates; D013462:Sulfur Radioisotopes; C012036:sodium sulfate