EFFECT OF SODIUM ETHYLENEDIAMINETETRA-ACETATE (NA2EDTA) ON HISTOCHEMICAL DEMONSTRATION OF SOME ENZYME ACTITIVIES IN NEONATAL MOUSE MOLAR TISSUES

Décalcification of neonatal mouse tissues, including the first molar germs, by 10 per cent ethylenediaminetetra-acetate (Na2EDTA) containing 7.5 per cent polyvinylpyrrolidone (PVP) was found to increase the histochemical reactions of lactate and malate dehydrogenase activities, as compared with non-decalcified preparations. The activity of glucose-6-phosphate dehydrogenase was not significantly affected by the demineralization procedure. Adenosinetriphosphatases (ATPases) in the endothelial cells and in the nuclei of most of the cells in the cryostat sections (8 μ) showed enhanced activities after the EDTA-treatment (48 hours at 4° C). ATPase in matrix-forming odontoblasts and ameloblasts, however, was consistently inhibited. The biochemical test indicated that the EDTA- and PVP-solutions, according to Fullmer (1966), allowed only a trace amount of protein leakage into the decalcification fluid. Preservation and retention of protein molecules and a simultaneous removal of contaminating ions and de-masking of active sites of the enzymes might be responsible for some of the effects observed in enzyme histochemical registrations. © 1969 Springer-Verlag.