Abstract
Proteoglycans stained specifically with cuprolinic blue have been visualized in electron micrographs of bovine arterial tissue. Three differently sized proteoglycan-cuprolinic blue precipitates, designated as types I, II, and III, could be detected in the extracellular matrix. The precipitates could be distinguished by their length, width, area, topographical distribution, and their characteristic association with other matrix components. By taking into account the available biochemical data and the individual susceptibilities of the precipitates towards specific glycosaminoglycan-degrading enzymes, each type of proteoglycan-cuprolinic blue precipitate could be attributed to a proteoglycan population containing dermatan sulfate, chondroitin sulfate, or heparan sulfate as its main glycosaminoglycan component.