Effects of chondroitin sulfate and sodium hyaluronate on chondrocytes and extracellular matrix of articular cartilage in dogs with degenerative joint disease

Samples of articular cartilage of femur, tibia and patella of 15 dogs with experimentally induced degenerative joint disease (DJD) were microscopically analyzed. Animals were distributed into three groups (n=5): the control group received no medication; the second group was treated with chondroitin sulfate and the third received sodium hyaluronate. Samples were processed and stained with HE and toluidine blue for morphological evaluation. The metabolic and proliferative activity of the chondrocytes was evaluated by the measurement of nucleolar organizer regions (NORs) after impregnation by silver nitrate. Significant differences were not observed (P>0.05) in the morphology among the groups, however, the group treated with sodium hyaluronate had a higher score suggesting a trend to a greater severity of the lesions. Significant differences were not observed (P>0.05) in the measurement of NORs, cells and NORs/cells among the groups. Although differences were not significant, sodium hyaluronate group showed higher NOR and cell counts which suggested an increase of the proliferation rate of chondrocytes. In addition, a higher NOR/cell ratio in the group treated with chondroitin sulfate suggested that this drug may have stimulated the metabolic activity of the chondrocytes, minimizing the lesions resulting from DJD. Foram utilizadas amostras de cartilagem articular do fêmur, tíbia e patela de 15 cães com doença articular degenerativa (DAD), induzida experimentalmente. Foram constituídos três grupos de cinco animais: grupo 1 - controle, não medicado; grupo 2 - tratado com sulfato de condroitina e grupo 3 - tratado com hialuronato de sódio. As amostras foram processadas e coradas pelas técnicas de HE e de azul de toluidina para avaliação das alterações morfológicas, e impregnadas pelo nitrato de prata para análise da atividade metabólica e/ou proliferativa dos condrócitos, por meio da visualização e quantificação de regiões organizadoras do nucléolo (NORs). Não foram notadas diferenças significativas (P0,05) na contagem de NORs, células e NORs/célula entre os grupos. As maiores contagens de NORs e de células no grupo tratado com hialuronato de sódio sugeriram aumento da taxa de proliferação dos condrócitos. A maior relação de NORs/célula obtida no grupo tratado com sulfato de c