Influence of diphenylhydantoin on isotope release and bone enzymes in vitro

The acute effect of diphenylhydantoin isotope release in an in vitro system using mouse calvaries was studied. A depressive effect on bone resorption was found involving radioactive calcium as well as tritiated proline. Bone resorption and formation were further investigated by semiquantitative histochemistry. Depressed activity of both alkaline and acid phosphatase was found, indicating a direct inhibitory effect of diphenylhydantoin on bone turnover.