The effects of precursors of glycosaminoglycans (GAG) and chondroitin sulphate A (CS) on the histomorphometry of normal articular cartilage and with experimental degenerative joint disease (DJD) in dogs were evaluated. The groups were constituted as follows: normal joints were not undergone to the surgical procedure and left osteoarthritics that suffered surgical intervention. These were then distributed into joints that did not receive drug treatment and those that received: normal (N) (n = 5); NGAG (n = 5), and NCS (n = 4); and osteoarthritics: O (n = 5); OGAG (n = 5); and OCS (n = 4). Cartilage sections of the femur, tibia, and patella were used in this study. In normal groups (N, NGAG, and NCS) no lesions were found that could characterize DJD, although the cellularity was shown to be slightly diminished in NGAG and NCS, in relation to N. Characteristic DJD disorders were identified in variable degrees among osteoarthritic groups and were more severe in O. There was marked reduction of the number of chondrocytes in group O, as compared to the normal groups, while treated osteoathritic groups showed similar cellularity to that of normal groups. These results were supported by the analysis of the index of proportion (IP), which was high in O, indicating less synthesis of proteoglycans. These results suggest that chondroitin A sulphate acted on osteoarthritic cartilage in a more efficient way than glycosaminoglycan precursors, reducing the loss of proteoglycans caused by the degenerative process, stimulating cellular viability and metabolic activity.
dog; degenerative joint disease; glycosaminoglycan precursors; chondroitin sulphate; articular cartilage
