DISTRIBUTION OF GLYCOSAMINOGLYCANS IN THE AQUEOUS OUTFLOW SYSTEM OF THE CAT

  • 1 January 1982
    • journal article
    • research article
    • Vol. 22  (3) , 319-329
Abstract
Although glycosaminoglycans (GAG) were postulated to play a role in the regulation of intraocular pressure, structural localization of specific varieties of GAG in the outflow system is necessary before their precise role can be determined. The outflow system of the cat was stained with ruthenium red to identify GAG with the EM. The composition of the ruthenium red-stainable material was determined by predigestion of tissues with testicular hyaluronidase, neuraminidase, or papain. Testicular hyaluronidase-sensitive GAG were located on the surfaces of the endothelial cells in the trabecular meshwork and aqueous plexus, within their basal laminae, and in the amorphous tissue of the trabecular beams and tissue adjacent to the aqueous plexus. Collagen and elastic fibers throughout the outflow system were also associated with ruthenium red-stainable material that was resistant to testicular hyaluronidase. Connective tissue GAG, but not endothelial associated GAG, were demonstrated to be complexed to protein, since they were disrupted by papain treatment. Neuraminidase-sensitive material (sialoglycoprotein) was identified only on the lumenal surface of the endothelial cells of the aqueous plexus. The complex distribution of GAG and other polyanions in the outflow system of the cat suggests that these macromolecules may serve > 1 function.