Histochemical Studies of Rheumatic Conditions: I. Observations on the Fine Structures of the Matrix of Normal Bone and Cartilage

Abstract

Three enzymes namely collagenase, hyaluronidase and trypsin were used for the differential removal of the ground substance components from histological sections. This was followed by specific staining methods for these components to see the extent to which they had been attacked by their enzymes. The articular cartilages of apparently healthy human knee joints obtained at autopsy were studied. After suitable prepn. and action by these enzymes, various staining methods were employed. Ca inhibited the action of collagenase. The polysaccharide content of hyaline articular cartilage delayed but did not inhibit the action of collagenase. If the polysaccharide was first removed the effect was complete and rapid. Ca present in the calcified zone of articular cartilage inhibited both collagenase and hyaluronidase. The difference in enzyme reactions between calcified and uncalcified tissues was apparent in vivo in the methods used by the body for their breakdown. Evidence supports the view that the Ca and the collagen in particular, the chondrin and the Ca almost as certainly, and the chondrin and the collagen less clearly, are chemically linked rather than merely close neighbours.