The interference of nucleotide metabolism induced by ~-arabino-hexos-2-u~ose (glucosone), 2-deoxy-2-fluoro-D-glucose (fluoroglucose) and, for comparison, 2-amino-2-deoxy-~-glucose (glucosamine) was studied in suspension cultures of TA3 mammary tumor cells. High-performance liquid chromatography, [I4C]uridine labeling and enzymatic analyses revealed that glucosone is metabolized to the U D P derivative leading to a diversion of [I4C]uridylate from UTP into UDP-glucosone. The accumulation of UDP-glucosone, that was measured in TA3 as well as AS-30D hepatoma cells, was associated with a depletion of UTP pools to less than 15'%; of control and a reduction of CTP contents to one third. UTP and CTP deficiency could be rapidly rcversed by addition of uridine to the cell suspension.Fluoroglucose acted both as a uridylate-trapping and as a guanylate-trapping hexose analog lowering the cellular contcnts of UTP and GTP to 5 % and 27 of control, respectively. The lowering of GTP was accompanied by an increase in total acid-soluble guanine nucleotides and a diversion of 84% of the [14C]guanylate into GDP-fluoroglucose. As compared to fluoroglucose and glucosone, glucosamine was less effective in TA3 cells in decreasing the content of UTP. The uridylate-trapping effect of glucosamine was in part compensated by the most active expansion of the acid-soluble uridylate pool; this reflects an enhanced rate of dc m v o pyrimidine synthesis that could be suppressed by the inhibitor 6-azauridine.As a side effect probably resulting from phosphate trapping, glucosone, fluoroglucose, and glucosamine depressed the levels of ATP and of total adenine 5'-nucleotides to a similar though moderate extent.The depletion of UTP, induced by these C-2-modified D-glucose analogs, and additionally of GTP in the case of fluoroglucose, represent a metabolic lesion that may explain their growth inhibitory and cytotoxic effects.Several C-2-modified D-glucose analogs are phosphorylated by hexokinase [l-31; some of them are metabolized further to U D P and/or GDP derivatives [4-61. Tntracellular formation and accumulation of the respective sugar 6-phosphate can result in a fall of inorganic phosphate triggering adenine nucleotide catabolism as one of its consequences [7 -91. Diversion of uridylate for the synthesis of UDP-sugar analogs leads to a lowering of cellular UTP levels and to a consecutive enhancement of the rate of de novo pyrimidine synthesis [lo]. The UTP depletion is followed by an inhibition of RNA synthesis [I I], while some of the C-2-modified UDPDedicated to Professor H. Holzer on the occasion of his 60th birthday. Abhreviutions. Glucosone, ~-arahino-hexos-2-ulose ; FGlc, fluoroglucose, 2-deoxy-2-fluoro-~-g~ucose; GlcN, glucosamine, 2-amino-2-deoxy-D-glucose; 6-AzaUrd, 6-azauridine; CAMP, CGMP, CUMP, sum of total acid-soluble adenine, guanine, and uracil 5'-nucleotides, respectively ; GDPMan, GDP-mannose; UDPGlc, UDP-glucose; UDPHexNAc, UDP-N-acetylhexosamines.Enzymes. Alkalinc phosphatase (EC 3.1.3.1): glucose-6-phosphate deliydrogenase (...