Richardson T M
Invest Ophthalmol Vis Sci. 1982 Mar;22(3):319-29.
Although glycosaminoglycans (GAGs) have been postulated to play a role in the regulation of intraocular pressure, structural localization of specific varieties of GAGs in the outflow system is necessary before their precise role can be determined. In this study, the outflow system of the cat was stained with ruthenium red to identify GAGs with the electron microscope. The composition of the ruthenium red-stainable material was determined by predigestion of tissues with testicular hyaluronidase, neuraminidase, or papain. Testicular hyaluronidase-sensitive GAGs 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 GAGs, but not endothelial cell-associated GAGs, 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 GAGs and order polyanions in the outflow system of the cat suggests that the these macromolecules may serve more than one function.
尽管有人推测糖胺聚糖（GAGs）在眼压调节中发挥作用，但在确定其确切作用之前，需要先明确特定种类GAGs在房水流出系统中的结构定位。在本研究中，用钌红对猫的房水流出系统进行染色，以便通过电子显微镜识别GAGs。通过用睾丸透明质酸酶、神经氨酸酶或木瓜蛋白酶对组织进行预消化，来确定钌红可染色物质的成分。对睾丸透明质酸酶敏感的GAGs位于小梁网和房水静脉丛内皮细胞表面、其基膜内、小梁束的无定形组织以及与房水静脉丛相邻的组织中。整个房水流出系统中的胶原纤维和弹性纤维也与对睾丸透明质酸酶有抗性的钌红可染色物质相关。已证明结缔组织GAGs而非内皮细胞相关GAGs与蛋白质复合，因为它们在木瓜蛋白酶处理后被破坏。仅在房水静脉丛内皮细胞的管腔表面发现了对神经氨酸酶敏感的物质（唾液糖蛋白）。猫房水流出系统中GAGs和有序多阴离子的复杂分布表明，这些大分子可能具有多种功能。
