The injection of ethanol (70 mmol/kg body weight) into male Wistar rats fed ad libitum caused an increase within 15 min in the liver inorganic pyrophosphate (PPi) content from 0.012 +/- 0.001 mumol/g (wet weight) to 0.029 +/- 0.001 mumol/g. The injection of acetate (20 mmol/kg body weight) increased the liver PPi to 0.157 +/- 0.075 mumol/g in 15 min. The alcohol dehydrogenase inhibitor 4-methylpyrazole blocked the accumulation of acetate and the increase in PPi was prevented. Disulfiram, an inhibitor of aldehyde dehydrogenase, did not prevent changes in redox state, but the accumulation of acetate in the liver was decreased and the increase in liver PPi content was diminished (0.019 +/- 0.003 mumol/g). These data suggest that the increase in PPi observed after injection of ethanol may be due to the activation of the acetate produced during ethanol and acetaldehyde oxidation.