[Proof of glycosaminoglycans in the corneal endothelium]

Abstract

The corneal endothelium of three species (man, dog, and guinea pig) was examined for glycosaminoglycans by using TEM, REM, and EDAX (energy-dispersive analysis of X-rays). Since no clear results can be determined by using ruthenium red (RR) alone, a testicular hyaluronidase was used to digest the glycocalyx. After incubation with hyaluronidase, the dark RR borderline of the outer leaflet of the cell membrane became more fluffy when examined by using TEM and REM. When EDAX was applied, the Ru peak became smaller compared with the S peak. These impressive results had not been found when the material was fixed in glutaraldehyde for 24 h before incubation. Considering the individual results, it can be concluded that RR, even wouthout OsO4, marks the acid groups of glycosaminoglycans that might be in the cell membrane, as well as other acid groups. There was no difference in the results among the three species used in this experiment. Some pictures showed that RR/OsO4 penetrates through the intercellular space into the Descemet's membrane.