Stimulation of nonbiliary, intestinal excretion of hexachlorobenzene in rhesus monkeys by mineral oil

Four rhesus monkeys were administered various doses of hexachlorobenzene (HCB) po, to achieve widely varying adipose tissue levels. One month later, each animal was provided with a bile duct bypass allowing for interruption of the enterohepatic circulation (EHC). Effects of mineral oil-supplemented diet and/or interruption of the EHC on urinary, biliary, and fecal excretion of HCB and its metabolites were quantified. Urinary excretion of HCB was not affected by mineral oil but was reduced 20 to 60% by interruption of the EHC. Similarly, biliary excretion of HCB was also reduced 25 to 60% by interruption of the EHC and was not altered by mineral oil. Fecal excretion was increased about fivefold by mineral oil, whereas interruption of the EHC had no effect on the amount of HCB in feces. Results demonstrate that interruption of the EHC reduced urinary and biliary excretion of HCB metabolites, whereas mineral oil specifically stimulated intestinal excretion of the parent compound.