AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 1 30-G33, Copyright © 1980 by American Physiological Society
A physiological model for hepatic metabolism of transferrin-bound iron
R. G. Batey, K. Williams and J. P. Milsom
Hepatic iron and transferrin uptake following intravenous injection of
purified native rat transferrin has been studied in the rat. Livers were
removed at varying time intervals postinjection and were fractionated by
isopycnic density gradient centrifugation. Neither 59Fe or 125I (labeling
transferrin) appeared in the lysosomal or mitochrondrial fractions at any
stage up to 14 days. 59Fe first appears in the supernatant zone of the
sucrose gradient and with increasing time postinjection passes through
regions of increasing density. By 16 h 59Fe became established at a density
of 1.10 g/cm3 and it was identified as ferritin. Ferritin persisted labeled
with 59Fe for up to 14 days. The study suggests hepatic iron uptake does
not involve endocytosis. Iron is incorporated into ferritin of increasing
density. This model can be used for the study of iron metabolism in human
biopsy samples.
