RESUMO
15-day-chick-embryo fibroblasts and chondroblasts were cultured in the presence of high and low molecular weight exogenous hyaluronic acid (HA). Growth range and incorporation of radiolabelled sulphate and proline were determined. HA reduced cell proliferation to about 75% of controls, while incorporation of radiolabelled sulphate and proline was higher in HA-treated cultures of both chondroblasts and fibroblasts. The effect was not due to the polyanionic or polymeric nature of the molecule and appeared to be highly specific for HA.
Assuntos
Cartilagem/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Ácido Hialurônico/farmacologia , Animais , Cartilagem/citologia , Cartilagem/metabolismo , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Colágeno , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibronectinas , Peso Molecular , Prolina/metabolismo , Biossíntese de Proteínas , Sulfatos/metabolismo , TrítioRESUMO
The effect of the intraarticular sodium hyaluronate (HA) injection on the osteoarthritic knee joint has been evaluated in dogs using an experimental model of osteoarthritis induced by sectioning the anterior cruciate ligament. Seven weeks after surgery, the damage, graded according to Mankin's scale, was significantly reduced in knee joints treated with HA from the second week postsurgery compared to untreated joints. When intraarticular HA therapy was initiated after the seventh week, osteoarthritis progression was still reduced compared to controls. Both morphology and morphometry showed a beneficial effect of HA on the cartilage response to the damage, as well as a clearcut inhibitory effect on the development of the fibroblastlike cell layer on the articular cartilage in untreated joints. The beneficial effects on the cartilage integrity and response to osteoarthritic damage might be related to a primary effect of HA on the cartilage surface. However, these effects do not exclude the possibility that, in addition, HA might act on the synovial membrane by limiting the synovial reaction.
Assuntos
Ácido Hialurônico/uso terapêutico , Articulação do Joelho/patologia , Meniscos Tibiais/patologia , Osteoartrite/tratamento farmacológico , Animais , Contagem de Células , Citoplasma/ultraestrutura , Modelos Animais de Doenças , Cães , Fibroblastos/patologia , Ácido Hialurônico/administração & dosagem , Processamento de Imagem Assistida por Computador , Injeções Intra-Articulares , Necrose , Osteoartrite/patologia , Coloração e RotulagemRESUMO
An established anterior cruciate ligament deficiency-induced articular cartilage degeneration was used to evaluate the effects of intrasynovial injection of hyaluronic acid upon cartilage destruction. In this study, proteoglycan solubility under associative and dissociative conditions was compared in two treatment protocols at intervals of seven, 13, and 17 weeks after surgical breakage of the anterior cruciate ligament in 2.5-year-old Beagle dogs. Untreated joints showed a marked increase in both total soluble glycosaminoglycan (GAG measured as uronic acid) and in the associative fraction. In both treated groups, there was a reduced amount of soluble GAG. Cessation of treatment after seven weeks caused gradual regression, with an increasing amount of CaCl2-soluble material in the associative fraction, while inception at seven weeks gave biochemical evidence of reversal, with increasing GAG present in the guanidine-soluble (dissociative) fraction on the insoluble residue. The protective effects of hyaluronic acid suggest the potential clinical application of this therapy in retarding the advance of osteoarthritis.
