The significance of the ultrahistochemical demonstration of phosphatases for the interpretation of the function of bone cells.

The authors carried out an ultrahistochemical investigation of alkaline and acid phosphatase in individual structures of mature bone tissue. They thus supplemented their previous study of the ultrastructure of bone cells and intracellular material, especially with regard to the morphological and functional relationships of the structural components of bone. The results indicate that AlPhase is a much more important enzyme, not only for the synthesis of the bone matrix, but also for the resorptional process of bone, than is generally assumed. AlPhase occurs both intra- and extracellularly in both functional stages of bone metabolism--synthesis and resorption--but usually differs in the distribution of the reaction product in various phases of bone remodelling. The findings are in many respects consistent with the results of the latest biochemical and enzymological investigations of bone tissue.