VARIATIONS IN DEHYDROGENASE AND NEOTETRAZOLIUM REDUCTASE (DIAPHORASE) ACTIVITIES IN VARIOUS BUFFERS STUDIED QUANTITATIVELY IN FROZEN SECTIONS

Open Access
Publisher Website
Google Scholar
Abstract
A quantitative study has been made in frozen sections of rat liver of the behavior of certain NAD+- and NADP+-linked dehydrogenases and the corresponding neotetrazolium reductases under histochemical conditions in phosphate, Tris and metaborate buffers. The rates of reaction were considerably decreased, though to variable extents, its metaborate buffer, with the exception of NADH-neotetrazolium reductase and the NADP+-linked glucose 6-phosphate and 6-phosphogluconate dehydrogenases. Glyceraldehyde 3-phosphate dehydrogenase could not be demonstrated with neotetrazolium as electron acceptor. Formazan production by both lactate and β-hydroxybutyrate dehydrogenases in phosphate and Tris buffers was almost as rapid as by NADH-neotetrazolium reductase, suggesting that in parts of the section the latter reaction was the rate-limiting step in these two cases.