Open AccessLocation and chemical composition of anionic sites in Bruch's membrane of the rat.
Author(s) -
Richard M. Pino,
Edward Essner,
Linda C. Pino
Publication year - 1982
Publication title -
journal of histochemistry and cytochemistry/the journal of histochemistry and cytochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.971
H-Index - 124
eISSN - 1551-5044
pISSN - 0022-1554
DOI - 10.1177/30.3.6174564
Subject(s) - ruthenium red , basal lamina , lysozyme , bruch's membrane , chemistry , hyaluronidase , staining , biochemistry , chondroitin sulfate , lamina lucida , heparan sulfate , microbiology and biotechnology , glycosaminoglycan , retinal pigment epithelium , biology , anatomy , retinal , enzyme , ultrastructure , genetics , organic chemistry , calcium
The location and chemical composition of anionic sites in Bruch's membrane (BM) were examined using cationic probe molecules demonstrable in electron microscopic preparations and tissue digestion with specific degradative enzymes. Ruthenium red and native lysozyme revealed densities distributed at regular intervals in two major components of BM: the basal laminae of the retinal pigment epithelium (RPE) and choriocapillary endothelium (EN). Staining was not observed with succinylated lysozyme (anionic). Colloidal iron also failed to stain BM components. Following crude heparinase treatment at 43 degrees C (specific for heparan sulfate) anionic sites in the RPE basal lamina were not demonstrable with either ruthenium red or native lysozyme. Sites in the EN basal lamina were not affected. Chondroitinase treatment removed almost all of the ruthenium red-positive material in the EN basal lamina; lysozyme binding here was markedly reduced. No changes were observed in the RPE basal lamina after chondroitinase digestion. There was no morphological evidence for site removal by either neuraminidase or leech hyaluronidase, although a detachment of the RPE from BM often occurred after incubation of eye tissue in the latter. Pronase E removed all stainable material. These findings indicate that anionic sites in BM consist to a large extent of chondroitin sulfates and heparan sulfate.