Toggle Main Menu Toggle Search

ePrints

Histidine-stimulated divalent metal uptake in human erythrocytes and in the erythroleukaemic cell line HEL.92.1.7

Lookup NU author(s): Professor Fiona Oakley

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

The uptake of 65Zn by human erythrocytes was investigated in the presence of high (40 mM) and low (5 mM) concentrations of histidine and 0-500 microM cobalt, nickel, manganese and zinc. Varying concentrations of metal mono- and bis-histidine complexes will be formed and the inhibition of 65Zn uptake could be correlated with the calculated complex concentrations to investigate competition between metals. For each metal, the calculated concentrations of bis-histidine complex giving 50% inhibition of 65Zn uptake were similar at both 5 mM and 40 mM histidine. Manganese-bis-histidine appeared to have a much higher affinity for the binding site than the other metal-bis-histidine complexes, which had similar affinities to each other. Studies of the inhibition of histidine-stimulated 54Mn uptake by the addition of manganese confirmed that manganese-bis-histidine does act as a substrate for the transporter in a similar fashion to the other metals studied. In addition, human erythroleukaemic cells (HEL cells) were used as a model for erythroid precursor cells. L-histidine, but not D-histidine, stimulated 65Zn uptake in a saturable fashion. The other metals competed with zinc in a similar manner to that seen in erythrocytes, and the affinity for manganese-bis-histidine was much greater than for the bis-histidine complexes of the other three metals. Both the capacity for metal transport per cell, and the affinity of the transporter for the metal-bis-histidine complexes, were much greater in the HEL cells than in the erythrocyte. It is suggested that histidine-stimulated metal transport may play a role in the supply of metals to maturing erythroid cells.


Publication metadata

Author(s): Oakley F; Horn NM; Thomas AL

Publication type: Article

Publication status: Published

Journal: Journal of Physiology

Year: 2004

Volume: 561

Issue: 2

Pages: 525-534

ISSN (print): 0022-3751

ISSN (electronic): 1469-7793

Publisher: Elsevier Masson

URL: http://dx.doi.org/10.1113/jphysiol.2004.072389

DOI: 10.1113/jphysiol.2004.072389


Altmetrics

Altmetrics provided by Altmetric


Actions

    Link to this publication


Share