Open AccessMultisite control of the Crabtree effect in ascites hepatoma cells
Author(s) -
RodríguezEnríquez Sara,
Juárez Oscar,
RodríguezZavala José S.,
MorenoSánchez Rafael
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02140.x
Subject(s) - fructose , intracellular , oxidative phosphorylation , fructolysis , chemistry , cytosol , biochemistry , galactose , glycerol , fructose 2,6 bisphosphate , glycolysis , metabolism , enzyme , phosphofructokinase
AS‐30D hepatoma cells, a highly oxidative and fast‐growing tumor line, showed glucose‐induced and fructose‐induced inhibition of oxidative phosphorylation (the Crabtree effect) of 54% and 34%, respectively. To advance the understanding of the underlying mechanism of this process, the effect of 5 m m glucose or 10 m m fructose on the intracellular concentration of several metabolites was determined. The addition of glucose or fructose lowered intracellular P i (40%), and ATP (53%) concentrations, and decreased cytosolic pH (from 7.2 to 6.8). Glucose and fructose increased the content of AMP (30%), glucose 6‐phosphate, fructose 6‐phosphate and fructose 1,6‐bisphosphate (15, 13 and 50 times, respectively). The cytosolic concentrations of Ca 2+ and Mg 2+ were not modified. The addition of galactose or glycerol did not modify the concentrations of the metabolites. Mitochondria isolated from AS‐30D cells, incubated in media with low P i (0.6 m m ) at pH 6.8, exhibited a 40% inhibition of oxidative phosphorylation. The data suggest that the Crabtree effect is the result of several small metabolic changes promoted by addition of exogenous glucose or fructose.