The enzyme histochemistry of developing odontoblasts in cattle, pigs and horses

Synopsis The histochemical distribution of some hydrolytic and oxidative enzymes in developing odontoblasts and subodontoblasts in cattle, pigs and horses has been observed in cryostat sections of teeth that have been decalcified with neutral EDTA.Undifferentiated dental epithelium and immature odontoblasts of the bell stage tooth germ showed lower levels of enzymatic activity as compared with the well-developed tooth germ.When the dentine matrix began to form, the young odontoblasts appeared to have a significantly positive reaction for acid phosphatase, and gradually other enzymes developed an activity at the top of the cusp.Odontoblasts as well as subodontoblastic-rich cells showed strong enzymatic activities for hydrolytic and oxidative enzymes, that is, they were strongly reactive for alkaline and acid phosphatase and lactate and malate dehydrogenases, and moderately reactive for other oxidative enzyme systems.It is suggested that the subodontoblastic layer is concerned with the biosynthesis of dentinal matrix as well as with the odontoblasts themselves.