[The distribution and characterization of sulfated-proteoglycans in the normal human lamina cribrosa]

The distribution and morphological characterization of the sulfated-proteoglycans in the normal human lamina cribrosa under the electron microscope after staining with cationic-dye (Cuprolinic-Blue) in critical electrolyte condition were studied. Three types of Cuprolinic-Blue positive filaments were identified associated with collagen in the lamina cribrosa according to their size, electro-density and their relation to the collagen fibrils. The thin and short Cuprolinic-Blue positive filaments (referred to as CB-1 filament in this communication) distributed over the collagen fibers in relatively regular fashion. The intermediate-sized Cuprolinic-Blue positive filaments (CB-2) were seen randomly associated with collagen fibers. The clusters of large CB-3 filaments were seen unevenly associated with loosely packed collagen fibers. The higher electron density of CB-2 and CB-3 filaments than those of CB-1 filaments were also demonstrated. Cuprolinic-Blue positive dots and blots as well as various sizes of filaments could be identified in the basal lamina surrounding the collagen beams and in the basement membrane of the blood vessels.