title: Cartilage proteoglycan alterations in an experimentally induced model of rabbit osteoarthritis.
abstract: Size distribution of cartilage proteoglycans (PG) extracted from control and osteoarthritic rabbit knees after partial meniscectomy was analyzed. In normal control knees, about 30% of PG molecules were in aggregate form and average sedimentation constant was 60S. No aggregates were found in osteoarthritic cartilage, whether ulcer, rim about ulcer, or distant normal-appearing cartilage was examined. Weight average sedimentation constants for PG subunits were similar to controls, 15S. Up to 70% of guanidinium-extractable PG could be extracted from osteoarthritic cartilage by using 0.5M guanidine HC1 (GuHCl); sedimentation characteristics of extracted PG were similar to those using 4.0M GuHCl. Absence of aggregates is consistent with a disorder of link protein, hyaluronic acid, or PG subunit hyaluronic acid binding sites. Absence of subunit degradation was an enexpected finding. The demonstrated ability of 0.5 M GuHCl to extract large amounts of PG from osteoarthritic cartilage will allow study of cartilage proteoglycans in their native nondissociated state.
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D006146:Guanidines; D006603:Hexuronic Acids / Q000302:isolation & purification; D007719:Knee Joint / Q000378:metabolism; D008722:Methods; D010003:Osteoarthritis / Q000378:metabolism*; D011509:Proteoglycans / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D014456:Ulcer / Q000378:metabolism
chemical_list: D006146:Guanidines; D006603:Hexuronic Acids; D011509:Proteoglycans