GLYCOSAMINOGLYCANS IN THE RAT AORTA - ULTRASTRUCTURAL-LOCALIZATION WITH TOLUIDINE BLUE-O AND OSMIUM FERROCYANIDE PROCEDURES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 105  (3) , 232-240
Abstract
Glycosaminoglycans (GAG) were implicated in the pathogenesis of sclerotic vascular disease. The localization of GAG in the rat aorta was examined by 2 different ultrastructural cytochemical approaches. These procedures apparently demonstrate anionic sites, with fixatives that contain either toluidine blue or ruthenium red, both cationic dyes and polysaccharides, proteoglycans and glycoproteins, with an osmium-ferrocyanide mixture that binds to vicinal diols. Both procedures stain a network of insoluble, 2-8-nm filaments that bridge collagen fibers, elastin, basement membranes and plasma membranes. These structures resist digestion with chondroitinase ABC and appear to be identical to the filaments that were previously demonstrated with ruthenium red. Focal 6-12-nm densities are present where filaments intersect. The large granules that are made visible with ruthenium red are not seen in toluidine blue or osmium-ferrocyanide preparations. A soluble and relatively amorphous component surrounds the tightly packed bundles of collagen in the media and is preserved and stained by toluidine blue and osmium-ferrocyanide mixtures.