Calcification XIV. Investigation of the Role of Chondroitin Sulfate in the Calcifying Mechanism. ∗ †

Abstract

Summary

1. Toluidine blue and protamine, like inorganic cations, produce a reversible inactivation of the mechanism of calcification. This inactivation is a function of the inhibitor to calcium ratio. 2. Up to a concentration of about 15 meq/L, calcium ion in the dye solution increases the intensity of metachromatic staining. Above this concentration there is a gradual decrease of metachromasia. 3. Under certain conditions, the calcifiability of bone sections parallels metachromasia. But it is possible, by raising the calcium ion concentration, to destroy metachromasia while increasing calcifiability, or by treatment with certain protein denaturants, to destroy calcifiability while enhancing metachromasia. 4. Synthetic chondroitin sulfate-collagen complexes have been found to exhibit behavior similar to that of rachitic bone cartilage with regard to metachromasia and calcifiability.