Abstract
1. A method is described of demonstrating in vivo the utilisation of radioactive sulphur35 and of radioactive phosphorus32 during bone growth and repair.
2. The relationship between labelled chondroitin sulphuric acid and labelled phosphate complexes has been studied, the importance and significance of vascularity and the localisation of the enzyme alkaline phosphatase being noted.
3. It was found that bone growth by external accretion, both epiphysial and periosteal, was accompanied by an increased utilisation of radioactive chondroitin sulphuric acid and calcium phosphate complexes.
4. During repair in a fracture site, although there was deposition of radioactive phosphate, no preferential localisation of radioactive sulphur was observed and the possible explanations of this are discussed.
