Iron absorption during the development of hexachlorobenzene-induced porphyria in rats.

The absorption of iron [59Fe-(FeSO4)] from jejunal loops was studied in rats after acute and subacute exposure to hexachlorobenzene (HCB). Female rats were given orally 100 mg HCB/kg body weight or fed a diet with 0, 500, 1,000, or 2,000 parts/10(6) HCB for 1 and 4 weeks. Male rats were fed on diets with 0 and 2,000 parts/10(6) HCB only. An increase in total urinary porphyrins and a decrease in the ratio of coproporphyrin to uroporphyrin in individual 24-h urine samples indicated different stages of porphyria in the rats at the time of determination of iron absorption. After acute oral administration of HCB, iron absorption decreased to about 70% of control values. After feeding the animals on HCB-containing diets, relative liver weight as well as total plasma protein increased depending on time and dose. The absorption of iron was not altered after 1 week of HCB exposure. After 4 weeks, the uptake of iron into the carcass decreased to less than 40% of control values, independently of dose and sex. The uptake of iron into the liver, expressed as percentage of the amount absorbed by the intestine, decreased significantly after 1 and 4 weeks of HCB feeding. No correlation could be observed between iron metabolism and urinary porphyrin excretion. The development of HCB-induced porphyria in rats is apparently not accelerated by an increased iron absorption.