Cartilagem articular de avestruz : um estudo estrutural e bioquimico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The articular cartilage is a hyaline connective tissue that contains cells and a great amount of extracellular matrix, which is composed of collagen, non-collagenous glycoproteins, and proteoglycans. This work aimed to describe the composition and organization of the extracellular matrix from articular cartilage of ostrich, which is a big bird with commercial importance and that commonly suffers of arthritis at the tarsometatarsical articulations when living in captivity conditions, teading to serious commitments to the animal s health, beyond the economical consequences. For this purpose. we have considered the articular cartilages of the proximal and distal surfaces of the tarsometatarsus. The proximal cartilage was divided into lateral, and intermediary-medial portions. From the distal surface only the central portion was analyzed. Structural analyses after toluidine blue staining showed presence of metachromatic and fibrilar components. The fibrils, intensely birefringent at polarization microscopy. were arranged in many directions, especially in distal cartilage. To extract the extracellular matrix components 4 M guanidinium chloride was utilized. The components were fractionated in DEAE-Sephacel and analyzed by SDS-PAGE. Quantitation of proteins and glycosaminoglycans was done utilizing colorimetric methods. The quantitative analysis revealed that the distal region, which is subjected to higher compressive forces, contaíns more proteins and glycosaminoglycans than the proximal region. The SDS-PAGE analysis of the fractions eluted from the DEAE-Sepachel showed the presence of proteíns with Mr from 17 to 121 kDa. In ali regions, polydisperse components wíth Mr around 67, 80-100, and 250-300 kDa, were found. These components probably correspond to the small proteoglycans fíbromodulin, decorín and biglycan. Glycosaminoglycans analysis in agarose-propylene diamine gel showed only the presence of chondroitin-suftate. The possible decorin found is a proteoglycan of chondroitin-sufate, and not dermatan-sulfate, as observed in other cartilages. Structurally the distal region exhibited ffbí11s arranged in several directions, probably because of a highest compressive strenght

ASSUNTO(S)

proteoglicanos matriz extracelular colageno

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