Abstract
A bone induction model was used to study the effect of different pretreatments and inhibitors added to the substrate media used for the histochemical demonstration of acid phosphatase activity. Two different acid phosphatases (AcP) were demonstrated. The AcP of matrix-producing cells exhibited resistance to pretreatment with EDTA while it was sensitive to tartrate added to the incubation medium. The AcP in dentin-resorbing cells was EDTA sensitive but resistant to tartrate. The AcP activities in resorbing and matrix-producing cells were generally sensitive to fluoride, Cu and Mo. In some of the dentinoclasts, fluoride-resistant AcP was observed. The results support previous investigations on normal bone formation, suggesting that at least 2 different isoenzymes of AcP exist. One of these seemed to be related to matrix production and mineralization of the new heterotopic bone.