DIETARY AND ETHANOL-INDUCED ALTERATIONS OF THE TOXICOKINETICS OF TOLUENE IN HUMANS

This study was undertaken to evaluate the influence of a carbohydrate restricted diet, a subacute ethanol intake, and their combined effect on the kinetics of toluene in humans. Eight healthy male volunteers we re exposed by inhalation at four different occasions to 200 mg/m(3) H- 2(8)-toluene for two hours at a work load of 50 W after a one week low (30%) carbohydrate (CH) diet or high (60%) CH diet with (+ EtOH) or w ithout (- EtOH) ethanol consumption (47 g ethanol) on the evening befo re exposure. Deuterium labelled toluene was used to measure the excret ion of hippuric acid originating from toluene separately from hippuric acid from other sources. The results indicated that subacute ethanol consumption combined with a carbohydrate restricted diet, may enhance the metabolism of toluene in humans at an exposure concentration of 20 0 mg/m(3). The cumulative amount of hippuric acid excreted in the urin e up to 20 hours after the end of exposure in % of the net uptake of t oluene was enhanced by 22% (p = 0.05) in the low CH + EtOH compared wi th the low CH-EtOH experiment. The apparent blood clearance of toluene was 37% higher in the low CH + EtOH than in the low CH-EtOH experimen t, but this effect was not statistically significant (p = 0.1). There were no significant changes in the kinetics of toluene as a result of a low carbohydrate diet alone. Neither did subacute ethanol intake wit hout the combination with a carbohydrate restricted diet influence the kinetics of toluene.