THE EFFECT OF MENADIONE AND PHENAZINE METHOSULFATE ON THE TETRAZOLIUM REDUCTION SYSTEM UNDER HISTOCHEMICAL CONDITIONS

Abstract

The influence of phenazine methosulfate and menadione on the activity of DPNH- and TPNH-tetrazolium reductase, succinic, lactic, and triphosphopyridine nucleotide-linked isocitric dehydrogenase were studied with reference to applied histochemistry. Fresh frozen sections of various tissues were employed in conjunction with nitro blue tetrazolium as the hydrogen acceptor. Phenazine methosulfate was found to produce a variable effect upon staining, enhancing it or suppressing it according to incubation conditions. Suppression was most pronounced with higher concentrations. Menadione had no suppressive influence and was useful in increasing tetrazolium reduction. Its usefulness is, however, limited unless a soluble factor, possibly DT-(DPNH-TPNH)-diaphorase, can be prevented from diffusing into the medium, and "nothing dehydrogenase" is selectively inactivated.