Calcification IX. Influence of Alkaline Earths on Survival of the Calcifying Mechanism.

Abstract

1. Rachitic bone cartilage slices which are suspended in basal medium at 36.5°C become slowly inactivated as shown by their subsequent inability to calcify. Major loss of calcifiability takes place in the first 7-8 hours with complete inactivation evident after about 12 hours. In the first 11 hours, small amounts of calcium or strontium exert a marked protective action against deterioration of the calcifying mechanism. Unlike calcium and strontium, comparable concentrations of magnesium and barium have no influence on the survival of the calcifying mechanism. 2. Beryllium in basal salt solution inactivates the calcifying mechanism, which can be prevented in part by inorganic phosphate. Manganese, cobalt, and nickel also inactivate the system when added to the basal salt solution. 3. Evidence to date favors the explanation that strontium and calcium ions protect the calcifying mechanism by forming a relatively stable compound with a component of the calcifying matrix essential for the mineralizing process, although an alternate explanation that these ions suppress a system responsible for inactivation cannot be excluded.