Effect of Beryllium on In Vitro Calcification of Cartilage

Summary

1. Beryllium in concentrations of 1.0 × 10⁻⁵M or greater is a potent inhibitor of the dephosphorylating activity of cartilage alkaline phosphatase. 2. In concentrations of 10⁻⁵M or greater, beryllium completely blocked in vitro calcification of cartilage when phosphorus was supplied as β-glycerophosphate, phenylphosphate or creatine phosphate. 3. When phosphorus was supplied as inorganic phosphate (the condition apparently obtaining in vivo), concentrations of beryllium sufficient to produce marked inhibition of alkaline phosphatase failed to interfere with in vitro calcification of cartilage. 4. The significance of these findings in relation to current theories of endochondral calcification and “beryllium rickets” is discussed.