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 rat es, indicating a high glycolytic activity. The utilization of ketone bodies , oxidation of endogenous glutamate, and oxidative phosphorylation were als o very active: tumor cells showed a high respiration rate (100 ng atoms oxy gen (min x 10(7) cells)(-1)), which was 90% oligomycin-sensitive. AS-30D tu mor cells underwent significant intracellular volume changes, which preserv ed high concentrations of several metabolites. A high O-2 concentration, bu t a low glucose concentration were found in the cell-free ascites liquid. G lutamine 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 oxide reductase and the enzyme block for ATP utilization mer e the sites that exerted most of the control of oxidative phosphorylation ( flux control coefficient 01.3-0.42). (C) 2000 Academic Press.