Ground Chondroitin sulfates

The dermis contains several types of cells, including fibroblasts, fat cells, macrophages, histiocytes, mast cells, and cells associated with the blood vessels and nerves of the skin. The predominant cell is the fibroblast, which is associated with biosynthesis of the fibrous proteins and ground substances such as hyaluronic acid, chondroitin sulfates, and mucopolysaccharides. 

Mast cells may disrupt (clasmatosis) and release their granules into the ground substance, liberating heparin and other chondroitin sulfates. Thus, the mast cell may be a storage form of the fibroblast. This release of granules is similar to secretion of many substances by other cells and would be a merocrine type of secretory activity. 

Fig. 1. Illustrating the various hierarchies of element involved in present considerations. At the top are shown the distinctive components of connective tissue. The ground substance, which contains the mucopolysaccharides, hyaluronate and chondroitin sulfate, has been studied chemically by Karl Meyer (150, 151) and by K. H. Meyer (158), among others, and electron optically by Gross (87), but this component does not receive significant further attention herein. Occasional reference is made to elastin, but the text considers principally the collagenous elements, shown in steps of increasing magnification.

Chondroitin sulfates are among the principal zoopolysaccharides of the ground substance in mammalian tissue and in cartilage. Cattle nasal cartilage has been the chief source for the preparation of chondroitin sulfate (f), generally extracted by calcium chloride 48) or potassium chloride solution 49). 

The interaction of the components of ground substance, the amorphous matrix especially found between the cells of connective tissue, has received the most study (65). Collagen particularly has been studied. Collagen, reticulin, and elastin fibers (proteins) are embedded in a viscid ground substance, which appears to contain dissolved proteins, hyaluronic acid, and sulfate esters of other zoopolysaccharides, especially of chondroitin sulfate. The soluble proteins present in connective tissue qualitatively are electro-phoretically similar to those of blood serum (66). The metachromasia shown by the ground substance (Chapter XI) results from the presence of acidic substances. Synovial (joint) fluid appears to be closely related to ground substance, but is virtually devoid of sulfate esters (67). 

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