Dehydrogenase histochemistry of N-ethyl-N-hydroxyethylnitrosamine-induced focal liver lesions in the rat--increase in NADPH-generating capacity.
Histochemical investigation of altered dehydrogenase enzyme activity in putative pre-neoplastic lesions induced by N-ethyl-N-hydroxyethylnitrosamine in the rat liver revealed a clear increase in NADPH-generating potential, most markedly within nodules. Glucose-6-phosphate dehydrogenase, malic enzyme and isocitrate dehydrogenase all showed elevated activity while the activities of succinate dehydrogenase and beta-hydroxybutyrate dehydrogenase were reduced. Alteration in enzyme activity suggested an adaptive shift in metabolism, the increase in levels of enzymes responsible for generation of reduced NADP possibly conferring enhanced drug detoxifying or cholesterogenic potential.
D000818:Animals; D004052:Diethylnitrosamine / Q000031:analogs & derivatives; D005227:Fatty Acids / Q000378:metabolism; D006651:Histocytochemistry; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D009249:NADP / Q000096:biosynthesis*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000032:analysis*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344
D005227:Fatty Acids; C023845:N-ethyl-N-hydroxyethylnitrosamine; D004052:Diethylnitrosamine; D009249:NADP; D010088:Oxidoreductases