D-Xylulose-Induced Depletion of ATP and Pi and Increase in PRPP in Isolated Rat Hepatocytes
Xylitol induces catabolism of ATP and depletion of Pi in the liver . These changes have been explained by the formation of millimolar concentrations of glycerol 3-P, which constitute a phosphate trap, similar to the one formed by fructose 1-P after the administration of fructose [reviewed in 2]. The formation of glycerol 3-P is explained by reduction of dihydroxyacetone-P, formed from xylitol, caused by an increase in the NADH/NAD+ ratio (Figure 1). The latter increase results from the oxidation of xylitol into D-xylulose. The aim of this work was to investigate if D-xylulose could provoke catabolism of ATP and depletion of Pi in hepatocytes. Indeed, since the metabolism of D-xylulose would not modify the NADH/NAD+ ratio, it would not be expected to provoke an accumulation of glycerol 3-P.
KeywordsPentose Phosphate Pathway Phosphate Ester Millimolar Concentration Purine Nucleoside Phosphorylase Thiamine Pyrophosphate
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