Enzyme histochemistry of induced heterotopic bone formation in guinea pigs

Abstract

In an experimental bone induction model in guinea-pigs, large amounts of heterotopic osteiod and bone were found after 21 days. A semiquantiative intrasectional analysis of oxidative and hydrolytic enzyme activities in the reaction zones showed that matrix-producing cells as well as dentine-resorbing cells had acid phosphatise activity. Leucine aminopeptidase activity was lower in dentinoclasts and macrophages than in matrix-producing cells, which may indicate a function of this enzyme in the production of bone matrix. A substrate-specific ATPase, as well as non-specific alkaline phosphatise and acid phosphatise were active in matrix-producing cells. A close relationship between resorbing cells and matrix-producing cells suggested an inductive mechanism during heterotopic bone formation.