[Glycosaminoglycans at the early stages of osteogenesis of the human long tubular bones]

Abstract

In anlages of long tubular bones of 68 human embryos and prefetuses (6-12 weeks of the prenatal development) changes in content and composition of glycosaminoglycans have been studied at early stages of osteogenesis. Histochemical reactions with brown basic, alcian blue, using the method of critical concentration of electrolyte and toluidine blue have been applied at various low values of pH with corresponding control experiments. For ultrastructural investigation of glycosaminoglycans localization the electron histochemical reaction with nitrogen acidic bismuth has been used. The most active synthesis of glycosaminoglycane is observed in chondrocytes of the proliferative zone of the epiphyseal cartilage of the anlages. In chondrocytes of the columnar zones the synthesis of glycosaminoglycans subsides, however, the mass of the substances increases on the surface of cytolemma of chondrocytes and in the intercellular matrix. During the process of development of the human long tubular bone analages contents of low sulfated glycosaminoglycans decrease with a simultaneous increase of concentration of these components, having a more acidic reaction. An essential role of polysaccharides and their complexes with proteins in ossification and mineralization of the human long tubular bone anlages is supposed.