[Effect of ethanol on the accumulation and excretion of mercury in rats].

Four groups of male Wistar rats, 4 animals in each, were fed a diet containing 3ppm of methylmercury in addition to ion exchange water containing 0% (control), 1%, 2% and 4% ethanol for drinking during the 40-day experimental period. Samples of urine and feces were collected every 8 days and the brain, liver and kidneys excised at the end (day 40) of the experimental period were analysed for concentrations of inorganic and organic mercury to investigate the effect of ethanol on the accumulation or excretion of mercury. Results obtained were as follows: 1) The volumes of drinking water and urine tended to decrease in concert with the increased percentconcentration of ethanol. However, there were no significant differences in the amount of feces between the rats given ethanol-containing water and the control rats given ion-exchange water alone. 2) The amounts of fecal inorganic mercury in rats given ethanol-containing water were not significantly different from those of control animals given water alone. However, significantly less urinary inorganic mercury was observed in the groups of rats given ethanol-containing water during the period of the last 8 days (33-40) of the experiment, when compared to the control group. 3) Significantly lower levels of urinary organic mercury were obtained during the period of the fourth 8 days (25-32) of the experiment for the group given 2%-ethanol-containing water, and during the periods of the second (9-16), third (17-25) and fourth (25-32) 8 days of the experiment for the group given 4%-ethanol-containing water, when compared to the control group. On the other hand, a significant increment of fecal organic mercury was observed during the period of the last 8 days (33-40) of the experiment for the groups given 2%-or 4%-ethanol-containing water. 4) No significant differeces were observed between the groups given ethanol-containing water and the control group given water alone for the mercury concentrations in the liver and kidneys. However, brain levels of inorganic and organic mercury tended to decrease with the increased percent-concentration of ethanol and significantly lower levels were present in the group given 4%-ethanol-containing water when compared to the control group. 5) Based on these results, the effects of ethanol on the distribution and excretion of mercury in rat tissues were discussed.