Structural analyses on the matrical organization of glycosaminoglycans in developing endocardial cushions.

摘要: Abstract Extracellular glycosaminoglycans (GAG) were examined in embryonic rat valvular primordia (cushion tissue) to determine if there are specific, situ, intermolecular associations of GAG and the passage migrating cushion cells alters matrical organization. Precursor incorporation studies colloidal iron staining controlled by acidified methylation, pH, polysaccharidase digestion indicated that both hyaluronate (HA) chondroitin sulfate (CHS) secreted into premigratory matrix with predominant being HA. Premigratory was revealed scanning electron microscopy after routine fixation as a microfibrillar stroma; addition cetylpyridinium chloride (CPCL) fixative resulted retention an additional component superimposed upon stroma. TEM analysis CPCL-dependent it composed intertwined 3-nm filaments, electron-dense, amorphous material, 30-nm granules. Collagen-like microfibrils associated primarily filamentous matrix. Ultracytochemical results obtained dialyzed binding regulated pH protease suggests filaments contain HA granules CHS protein. Commensurate cell formation migration, X-ray dispersive polyanionic histochemical criteria increased deposition postmigratory (i.e., transversed cells). Ultrastructurally, components became progressively restructured within wedge cells. In contrast matrix, fewer evident, while heavily studded collagen-like microfibrils. Physical controls confirmed variations between pre- matrices. These suggest modification organization heart may be correlated migration tissue mesenchyme.