Non-transferrin-bound iron in plasma or serum from patients with idiopathic hemochromatosis. Characterization by high performance liquid chromatography and nuclear magnetic resonance spectroscopy.
The nature of non-transferrin-bound iron in the plasma or serum of iron-overloaded hemochromatosis patients was studied by high performance liquid chromatography (HPLC) and high resolution nuclear magnetic resonance (NMR). 500-MHz proton Hahn spin-echo NMR spectra of plasma or serum, combined with the use of the iron chelator desferrioxamine, suggests complexation of iron ions with citrate and a possible involvement of acetate. Addition of FeCl3 to hemochromatosis samples broadened the NMR signals from citrate. HPLC analysis rigorously confirmed the presence of an iron-citrate complex in ultrafiltrates of plasma or serum studies with added FeCl3 or desferrioxamine supported this conclusion. It is proposed that non-transferrin-bound iron in the plasma of iron-overloaded patients exists largely as complexes with citrate and possibly also as ternary iron-citrate-acetate complexes. The presence of such complexes would account for the ability of non-transferrin-bound iron to be measurable by the bleomycin assay and for its rapid clearance from the circulation by the liver.
Grootveld
M
M
Department of Applied Chemistry and Life Sciences, Polytechnic of North London, United Kingdom.
Bell
J D
JD
Halliwell
B
B
Aruoma
O I
OI
Bomford
A
A
Sadler
P J
PJ
D000085:Acetates / Q000097:blood; D001761:Bleomycin; D002712:Chlorides; D002851:Chromatography, High Pressure Liquid; D002951:Citrates / Q000097:blood; D019343:Citric Acid; D003676:Deferoxamine; D005290:Ferric Compounds; D006432:Hemochromatosis / Q000097:blood*; D006801:Humans; D007501:Iron / Q000097:blood*; D009682:Magnetic Resonance Spectroscopy; D014168:Transferrin / Q000378:metabolism*; D014462:Ultrafiltration
D000085:Acetates; D002712:Chlorides; D002951:Citrates; D005290:Ferric Compounds; D014168:Transferrin; D001761:Bleomycin; D019343:Citric Acid; D007501:Iron; D003676:Deferoxamine; C024555:ferric chloride