Rapidity of Calcification in vitro. ∗

Abstract

Summary and Conclusions

1. In the presence of organic phosphate ester, calcification of hypertrophic rachitic cartilage slices occurs with great rapidity and at what appears to be an extremely low concentration of inorganic phosphate. The estimated concentration of inorganic phosphate ester is undoubtedly deceptive, because it does not indicate the concentration which prevails in the immediate vicinity of the slice and in the slice itself. This is probably extremely high because of degradation of organic phosphate ester by alkaline phosphatase in the bone slice, and the limited rate of diffusion of phosphate away from the slice. 2. Our results also indicate that in a very short time the outline of the final calcification pattern is formed, and the density of the bone salt deposit then increases with time.