Enhanced fecal elimination of stored hexachlorobenzene from rats and rhesus monkeys by hexadecane or mineral oil

The effect of various dietary treatments on the fecal excretion of [¹⁴C]-hexachlorobenzene (HCB) was studied in rats and rhesus monkeys. Cholestyramine and sesame oil failed to influence fecal excretion of HCB and/or metabolites. However, dietary administration of n-hexadecane (5%) increased fecal excretion of radioactivity 4-13-fold in rats and rhesus monkeys. Similarly, mineral oil in the diet (5%) of rhesus monkeys elicited a 6-9-fold increase in fecal excretion of HCB and/or metabolites. As a result of the mineral oil treatment, an enhanced depletion of HCB from blood and also of the stored HCB from adipose tissue was observed. The concentration of HCB in the blood declined in accordance with decreasing storage levels of HCB in adipose tissue. The major site of elimination of HCB and/or metabolites seemed to be the intestine; in particular, the cecum and the colon ascendens. Both hexadecane and mineral oil appeared to stimulate specifically this elimination pathway.