AGE-RELATED-CHANGES IN THE LOCALIZATION OF GLYCOSAMINOGLYCANS IN CONDYLAR CARTILAGE OF THE MANDIBLE IN RATS

There is little information available regarding the morphological and biomolecular characteristics of mandibular condylar cartilage. The pur pose of this study was to determine the age-related changes in the mor phology and immunolocalization of glycosaminoglycans (GAGs) in mandibu lar condyles. The mandibular condylar cartilages from 4-, 8-, 16-, 32- , and 64-week-old Wistar male rats were examined to verify the localiz ation of chondroitin-4-sulfate (Ch-4S), chondroitin-6-sulfate (Ch-6S) and keratan sulfate (KS) using an indirect immunofluorescent technique with three monoclonal antibodies for glycosaminoglycans, 2-B-6, 3-B-3 and 5-D-4, respectively. Morphologically, the condylar cartilage was a growth cartilage during growing periods, began to differentiate into articular cartilage from the central area of 16-week-old condyles, an d became mature articular cartilage at 32 weeks of age. A regional dif ference was found in the morphological features and distribution of GA Gs between the anterior, central, postero-superior and posterior areas of the condyles at each age. The immunohistochemical localizations of these three glycosaminoglycans showed age-related, morphology-depende nt changes, from growth cartilage to articular cartilage-like cartilag e. Immunoreactions for all of the antibodies decreased progressively w ith age in the interterritorial matrix, while the pericellular and ter ritorial matrix in the condylar cartilage of the mandible maintained r elatively higher immunoreactivity. In conclusion, age-related and regi onal differences in the localization of glycosaminoglycans Ch-4S, Ch-6 S, and KS were found in the mandibular condyles in rats, and these cha nges are believed to be related to functional and developmental requir ements.