Relationship of body weight to disposition of hexachlorobenzene in rats.

Male rats of various body weights were dosed twice with [14C]hexachlorobenzene (50 mg/kg, p.o.) in olive oil by gavage on 2 consecutive days. During 2 weeks after dosage, cumulative excretion into urine was about 1% of the dose and unrelated to body weight. Cumulative excretion into feces was 30 +/- 10% of the dose and decreased with increasing body weight. In contrast, the concentration of hexachlorobenzene in urine, feces, kidney, liver and adipose tissue 14 days after dosing were higher in larger than in smaller animals. However, the relative concentration, i.e. the concentration of hexachlorobenzene in urine, feces or tissue divided by the concentration of hexachlorobenzene in adipose tissue, eliminated most of the variability among individual animals. This allows direct comparison of dispositional data of animals with greatly differing body burdens.