title: Microinjury to the synovial membrane may cause disaggregation of proteoglycans in rabbit knee joint articular cartilage.
abstract: Proteoglycans (PGs) isolated from articular cartilage (AC) of mature rabbits subjected to two or more consecutive intraarticular (IA) injections of sterile saline 24 h apart showed an aggregation defect in the presence of excess hyaluronic acid (HA). Although the PG contents of experimental and control cartilages were indistinguishable, a higher proportion of PGs were extractable from the 3 X IA tissues, as assessed by uronic acid analysis. Proteoglycans from experimental and control cartilages when examined by Sepharose CL-2B chromatography showed two subunit populations, the smaller (KAV = 0.70) containing more ketatan sulphate than the larger (KAV = 0.31). Cultures of AC from IA joints released more 35SO4-labelled PGs into the media over 72 h than control tissues and consisted mainly of PG degradation products although 20% could aggregate in the presence of HA. Examination of PG aggregation 2 weeks after 2 X IA or 3 X IA injections showed that the defect initiated was still present; however, cartilage of immature rabbits was not affected by the 2 X IA procedure.
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D002850:Chromatography, Gel; D005688:Galactosamine / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006595:Hexosamines / Q000378:metabolism; D006820:Hyaluronic Acid / Q000378:metabolism; D006965:Hyperplasia; D007270:Injections, Intra-Articular; D007719:Knee Joint; D009924:Organ Culture Techniques; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits; D012965:Sodium Chloride / Q000008:administration & dosage; D013583:Synovial Membrane / Q000293:injuries* / Q000473:pathology
chemical_list: D006595:Hexosamines; D011509:Proteoglycans; D012965:Sodium Chloride; D005688:Galactosamine; D006820:Hyaluronic Acid; D005944:Glucosamine