Hepatic zinc in hemochromatosis

Abstract

Since an intestinal absorptive interaction between iron and zinc has been described in animals and humans, the possibility of increased accumulation of zinc as well as iron in the liver was studied in patients with hereditary hemochromatosis. Hepatic zinc was determined by atomic absorption spectrophotometry in liver biopsy specimens from 21 homozygotes for hemochromatosis, 21 normal liver samples from autopsies, and 15 cases of cirrhosis unrelated to iron overload. Mean hepatic zinc concentrations in the three groups were compared by one-way analysis of variance. Hemochromatosis patients had hepatic iron determinations by atomic absorption spectrophotometry, and iron absorption studies using 59Fe and total body counting had been previously documented in 18 of the 21 hemochromatosis patients. The mean hepatic zinc was significantly increased at 25.9 +/- 26.7 mumol/g (dry weight) in the hemochromatosis patients, as compared to 4.99 +/- 1.51 mumol/g in the control patients (p less than 0.05), and 2.13 +/- 1.13 mumol/g in the cirrhosis patients without iron overload (p less than 0.05). Hepatic zinc concentration was elevated in hemochromatosis patients who had either normal histology, fibrosis, and cirrhosis. Hepatic zinc concentration was not directly related to patient age, hepatic iron concentration, or iron absorption. In conclusion, hepatic zinc was increased approximately fivefold in patients with hemochromatosis. This finding suggests the concomitant hepatic accumulation of zinc as well as iron in this disorder, possibly by means of increased intestinal absorption of zinc and hepatic sequestration.