Evidence for zinc protection against 2,5-hexanedione toxicity by co-exposure of rats to zinc chloride

The protective role of zinc against the toxic effects of 2,5-hexanedione (2,5-HD), the main neurotoxic metabolite of n-hexane, was investigated by studying the interference of zinc on the toxicokinetics of 2,5-HD, Six groups of Wistar rats were exposed for 3 days to diets containing 2,5-HD, zinc chloride and 2,5-HD+zinc chloride. The amounts of pyrroles and free and total 2,5-HD in urine were determined using Ehrlichs's reagent and gas chromatography/flame ionization detection, respectively. The results show that after the first day of co-exposure (ZnCl2+2,5-HD) there was a significant decrease in the excretion of pyrroles and free 2,5-HD in rats exposed to the chemical mixture when compared to the pyrroles and free 2,5-HD excreted in rats exposed to 2,5-HD alone. However, no significant decrease was observed in the urinary excretion of total 2,5-HD (free 2,5-HD + preformed 2,5-HD). Suggestions are made about the role played by this metal ion in inhibiting pyrrole formation. Copyright (C) 2000 John Wiley & Sons, Ltd