Age-Related Changes in Glycosaminoglycans in the Rat Temporomandibular Joint

Abstract

     We investigated age-related changes in glycosaminoglycans (GAGs) in the rat temporomandibular joint (TMJ). The TMJ were removed from Sprague Dawley rats 3, 5, 10, 15, 30 and 50 weeks of age. Immunohistochemically, paraffin sections were treated with Mab 2B6, 3B3, 6B6 or 5D4 antibodies, and stained by the indirect immunoperoxidase technique. Biochemically, thd GAG composition was determined by electrophoresis on cellulose acetate strip, and the total amount of GAGs was measured as uroric acid.
     Immunohistochemical analysis revealed an intense reaction in the hypertrophic zone and mature cell zone of cartilage for chondroitin sulfate, in the condylar disc and articular zone for dermatan sulfate, and in the hypertrophic zone, mature cell zone and condylar disc for keratan sulfate. Although the relative amount of chondroitin sulfate decreased with age, dermatan sulfate and keratan sulfate increased.
     Biochemical analysis revealed that the GAGs were 14.3〜22.6% hyaluronic acid, 53.2〜66.8% chondroitin sulfate, 6.4〜14.4% dermatan sulfate, and 4.1〜18.1% keratan sulfate. Although the relative amount of hyaluronic acid and chondroitin sulfate decreased with age, dermatan sulfate and keratan sulfate increased. The total amount of the GAGs in the TMJ tended to decrease with age.