Mechanism of Calcification in Mammalian Bone

Abstract

WHEN supplies of calcium, phosphorus and various other humoral factors are adequate, calcification of mammalian bone is usually attributed to the local action of enzymes and to a template mechanism. These theories are not wholly satisfactory, because the enzymes are also found at sites where calcification does not occur and a variety of substances besides collagen of the appropriate molecular spacing can act as nucleating agents for the deposition of bone salts^1,2. An electrochemical mechanism may be involved in remoulding, for bone forms round the cathode of a small mercury cell implanted into a living dog femur³ and potentials are produced by piezo-electric effects resulting from stress in a formed bone^4,5. Such a mechanism does not, however, readily account for the initiation of calcification.