Substrate oxidation and ATP supply in AS-30D hepatoma cells.
The oxidation of several metabolites in AS-30D tumor cells was determined. Glucose and glycogen consumption and lactic acid production showed high rates, indicating a high glycolytic activity. The utilization of ketone bodies, oxidation of endogenous glutamate, and oxidative phosphorylation were also very active: tumor cells showed a high respiration rate (100 ng atoms oxygen (min x 10(7) cells)(-1)), which was 90% oligomycin-sensitive. AS-30D tumor cells underwent significant intracellular volume changes, which preserved high concentrations of several metabolites. A high O(2) concentration, but a low glucose concentration were found in the cell-free ascites liquid. Glutamine was the oxidizable substrate found at the highest concentration in the ascites liquid. We estimated that cellular ATP was mainly provided by oxidative phosphorylation. These data indicated that AS-30D hepatoma cells had a predominantly oxidative and not a glycolytic type of metabolism. The NADH-ubiquinol oxido reductase and the enzyme block for ATP utilization were the sites that exerted most of the control of oxidative phosphorylation (flux control coefficient = 0.3-0.42).
Rodríguez-Enríquez
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Departamento de Bioquímica, Instituto Nacional de Cardiología, Juan Badiano 1, Seccion XVI, Tlalpan, México, DF, 14080, Mexico. saren96@hotmail.com
Torres-Márquez
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Moreno-Sánchez
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D020155:3-Hydroxybutyric Acid / Q000378:metabolism; D000090:Acetoacetates / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D019069:Cell Respiration / Q000502:physiology; D003600:Cytosol / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006019:Glycolysis / Q000502:physiology; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured
D000090:Acetoacetates; D005973:Glutamine; D018698:Glutamic Acid; C016635:acetoacetic acid; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate; D006003:Glycogen; D005947:Glucose; D020155:3-Hydroxybutyric Acid