Changes in preference for NaCl following administration of 6-azauridine and 6-azauridine triacetate

Preliminary evidence in man has suggested that 6-azauridine triacetate (6-AzUrdTA) might adversely affect taste acuity. The production of measurable serum concentrations of homocysteine in rabbits treated with 6-AzUrdTA further suggested a mechanism for the possible adverse effects of this drug on taste, since administration of other thiol-containing drugs in man and animals had been shown to decrease taste acuity. Since changes in preferences for NaCl solutions have been shown to reflect changes in taste acuity in the rat, preference for NaCl solutions in rats treated with 6-AzUrdTA were measured in a two-bottle test. Detection and recognition thresholds were also measured in patients with scleroderma before and after the administration of 6-AzUrdTA. Serum copper and zinc concentrations were measured in both rats and man. Rats given 6-AzUrdTA exhibited a significantly greater intake of 0.30-M NaCl than control rats, who avoided this solution. This change was accompanied by a significant decrease in serum zinc concentrations. No significant changes in taste acuity occurred in the patients. These data suggest that administration of 6-AzUrdTA affects taste acuity in rats either through the addition of thiols or the depletion of zinc.