Cell cooperation on bone resorption in chronic otitis media.

Since collagen comprises over 90% of bone protein, collagenase appears to be a major factor in the resorption process of the organic matrix of bone. We have studied the mechanism of production of collagenase in cell cultures of rat skin fibroblasts and macrophages under various conditions. Production of collagenase by fibroblasts increased significantly with the addition of the conditioned medium obtained from the culture of endotoxin-activated rat peritoneal macrophages. This study concludes that the endotoxin-activated macrophages produced factor or factors which stimulate fibroblasts to produce collagenase.