Activities of enzymes of lipid metabolism in Morris hepatoma 7800 C1 cells.
(1) The rate of palmitate oxidation in the 7800 C1 Morris hepatoma cells was about 60% of the activity observed in hepatocytes. The stimulatory effect of glucagon in hepatocytes was not observed in the hepatoma cells. The rate of fatty acid synthesis from [2-14C]acetate in the hepatoma cells was 1/20 of the activity in hepatocytes. The conversion of [2-14C]acetate to cholesterol was not different in the two kinds of cell. (2) Acetyl-CoA carboxylase and fatty acid synthetase were significantly decreased in the hepatoma cells. The hepatoma cells had, however, raised activities of malate dehydrogenase (decarboxylating), and glucose-6-phosphate and 6-phosphogluconate dehydrogenases. (3) The activities of the enzymes were not affected by different concentrations of glucose or palmitate in the culture medium. Insulin, dexamethasone, triiothyronine and glucagon had no effect on the enzyme activities. This is in contrast to the adaptation of the peroxisomal beta-oxidation system, which is induced by fatty acids and modified by hormones.
Spydevold
O
O
Institute of Medical Biochemistry, University of Oslo, Norway.
Gautvik
K
K
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002784:Cholesterol / Q000096:biosynthesis; D064429:Fatty Acid Synthases / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology; D066298:In Vitro Techniques; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction; D010168:Palmitates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014407:Tumor Cells, Cultured / Q000201:enzymology*
D005227:Fatty Acids; D006728:Hormones; D010168:Palmitates; D002784:Cholesterol; D000429:Alcohol Oxidoreductases; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase; D005947:Glucose