title: Stearoyl-coenzyme A desaturase activity in Novikoff hepatoma.
abstract: The activities of microsomal stearoyl-CoA desaturation, NADH-cytochrome b5 reductase, NADH-cytochrome c reductase, and the content of cytochrome b5 were similar in livers of normal and host rats. On the other hand, stearoyl-CoA desaturation activity was absent in Novikoff hepatoma. The activities of NADH-cytochrome b5 and NADH-cytochrome c reductases in the hepatoma microsomes were 4.8% and 2.2%, respectively, of those in normal liver. Furthermore, in hepatoma microsomes, cytochrome b5 was absent. An active stearoyl-CoA desaturation was reconstituted only on addition of both cytochrome b5 and the terminal desaturase enzyme to the hepatoma microsomes. These results indicated that a complete absence of cytochrome b5 and terminal desaturase is responsible for the lack of stearoyl-CoA desaturation in Novikoff hepatoma microsomes.
mesh_terms: D000818:Animals; D003580:Cytochromes / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D051381:Rats; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism*
chemical_list: D003580:Cytochromes; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; D009247:NADH, NADPH Oxidoreductases