Histochemical Study of Oxidative Enzyme Systems in Teeth and Peridental Tissues

¹ Department of Pathology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts

A number of oxidative enzyme systems were demonstrated histochemically in teeth and peridental tissues of 14- to 106-day-old mice. After decalcification with EDTA, the unfixed tisues were cut in a cryostat (—18° C.) and the frozen sections then incubated at 37° C. in substrate solutions designed for the demonstration of enzyme activity. A ditetrazolium salt (Nitro-BT) served as the final electron acceptor. Marked DPNH diaphorase, TPNH diaphorase, succinic dehydrogenase, and lactic dehydrogenase activity were observed in the odontoblasts, the cells of the enamel organ, osteoclasts, osteoblasts, and young osteocytes. Moderate activity of isocitric dehydrogenase, malic dehydrogenase, and glucose-6-phosphate dehydrogenase was also noted. All of these enzymes were present in the dental pulp, cementocytes, and osteocytes, as well as in the periodontal membrane and periosteum. The findings have been described in detail and correlated with the structure and function of various cell types.