The accumulation of 99mTc-glucarate, an agent recently reported to localize in acutely infarcted myocardium, zones of acute cerebral injury and tumors, has been compared with 99mTc-gluconate in an in vitro system of cultured Chinese hamster ovary fibroblasts. The effects on accumulation of hypoxia and competition with fructose have been studied. Both labeled glucose analogs showed a two- to threefold enhanced accumulation in hypoxic cells relative to aerobic cells. No such enhanced accumulation under hypoxia was observed for the nonsugar tracers pertechnetate and 99mTc-DTPA. The presence of 20 mM fructose reduced the accumulation of 99mTc-glucarate by 30% (p = 0.067) and 99mTc-gluconate by 40% (p < 0.05) in hypoxic cells, but had no significant effect in aerobic cells. These results suggest that both compounds at least partially share a common mechanism of uptake and/or accumulation with fructose.