[Ultrastructure of the proteoglycan component of the extracellular matrix in the intact mammary gland and in benign and malignant mammary gland tumors].

Proteoglycans (PG) were revealed by electron microscopy using cation dyes, Alcian blue and safranin O. In intact mammary gland of dogs, each histogenetic type of cells had its specific features in the ultrastructure of pericellular matrix proteoglycan component. A thin-stitched net, consisting of small PG granules and thin filaments has been observed in the pericellular space of secretory epithelium. A well-proportioned PG net is absent near fibroblasts and macrophages. Net-like PG structure is found in the endothelium, pericytes and adventitial cells of blood capillaries. Visual changes in PG-containing extracellular matrix are observed in the epithelium of mammary gland tumors.