Effect of environmental temperature on tissue lead accumulation in mice repeatedly treated with lead acetate

The effect of environmental temperature on lead accumulation in tissues of mice repeatedly treated with lead acetate (2 mg/kg per day and 5 mg/kg per day) for 3 or 6 weeks was studied. In blood, kidney and liver, the amount of lead accumulated after 3 weeks of treatment was markedly higher in animals exposed to 22°C than those maintained at 35°C. Conversely, when the treatment was extended to 6 weeks, lead concentrations in the liver and kidney were equal or higher respectively, in the mice exposed to 35°C. In the brain, lead concentration was lower than that found in kidney and liver and it was independent of dose and ambient temperature after 3 weeks of treatment but increased when the treatment period was extended up to 6 weeks, the accumulation of lead being higher at 35°C than at 22°C. These results demonstrate that environmental temperature influences the amount of lead accumulated in some rodent tissues, and that the duration of the treatment modifies the effect produced by temperature, suggesting that the changes elicited during the period of acclimation to the hot environment could be responsible for these findings.