A cytochemical study of oxidative enzymes in Ehrlich ascites tumor cells

Cytochemical observation of the activities of diphosphopyridine nucleotide diaphorase (DPNH-D), triphosphopyridine nucleotide diaphorase (TPNH-D), succinic dehydrogenase (SDH) and a-glycerophosphate dehydrogenase (α-GDH) of Ehrlich ascites carcinoma cells were made and following results were obtained. The smeared cells showed moderate reactions and no marked difference in the intensity among the individual cells. The free floating cells were stained relatively faint but showed the differences in the staining intensity in individual cells. In the presence of benzalkonium, the reaction intensity proved to be intermediate between the smeared cells and free floating cells without benzalkonium and the differences in the staining intensity in individual cells were more marked. Observations revealed that the reaction intensity changes closely corelated with the stage of mitotic cycle of each cell. Namely, DPNH-D activity of the tumor cells, which generally hihger than that of leucocytes, increased remarkably in the end stage of interphase and decreases abruptly in mitotic stage reaching the lowest level in metaphase. After the metaphse the activity increased slightly and it is kept at almost the same level during the first half of interphase. This enzyme is localized mainly in the granules of the eytoplasm. The activity of TPNH-D showed the similar localizations as those of DPNH-D, though the reaction intensity is lower than that of DPNH-D. The activity of SDH of the tmnor cells is lower than that of leucocytes and its diformazan granules are localized in mitochondria. Its activity decreases in the mitotic stage the lowest level in metaphase and in the followed interphase it is kept in a almost constant low level. α-GDH activity of the tumor is lower than that of SDH but show the similar localizations as the latter.