Variations in Phosphatase and Inorganic Phosphorus in Serum During Fracture Repair

A study of the phosphatase concentration of the blood during the union of fractures seemed to us of interest because of the evidence that is accumulating that phosphorus metabolism is one of the important factors in the deposition of bone salts. Robison¹has shown that phosphatase, an enzyme extracted from bone and ossifying cartilage and in smaller quantities from other tissues, can liberate inorganic phosphorus by breaking down solutions of complex organic compounds of phosphorus, such as glycerophosphates and hexosephosphates. Calcification has been observed of rachitic bone immersed in solutions of these two salts.²It is Robison's hypothesis that the phosphatase available in the cells of bone and ossifying cartilage reacts with glycerophosphates or hexosephosphates in the blood. By this means there is produced a local increase in inorganic phosphorus in the region of these cells. This increase in phosphorus alters the equilibrium between calcium and phosphorus ions