Enzyme activities of rat connective tissue obtained from subcutaneously implanted polyvinyl sponge.

A great deal af the current interest in the connective tissues has been focused on the extracellular components of these tissues, particularly collagen and the mucopolysaccharides. Alterations in the amounts and in the physical and chemical properties of these extracellular components have been implicated as contributing factors in many abnormal and diseased states such as rheumatoid arthritis, atherosclerosis, silicosis, the “collagen diseases,” and aging. Changes in the amounts and properties of the extracellular substances are, in turn, ascribed to abnormalities in the metabolic processes of the connective tissue cells. Attempts to elucidate the nature of these abnormalities have been hindered by a lack of understanding of the normal metabolic processes of connective tissue. The chief barriers to such knowledge have been the low metabolic activities of most connective tissues and the difficulties in obtaining sizeable reproducible samples of relatively pure connective tissue amenable to study in vitro. Recently, Boucek and Noble (2) have described a technique for stimulating the formation of new connective tissue by the subcutaneous implantation of polyvinyl alcohol sponge. This technique permits the simple and reproducible sampling of large amounts of connective tissue in a relatively pure state, as judged by histological examination (2). In the present study homogenates of such material have been quantitatively assayed for a variety of enzymes. The results indicate that this connective tissue possesses a wide range of enzymatic activities including representatives of the three major pathways of carbohydrate metabolism, a variety of esterases, and a unique pattern of proteolytic enzymes characteristic of all the other types of connective tissue thus far examined.