The University of Southampton
University of Southampton Institutional Repository

Physiological transport of zinc

Physiological transport of zinc
Physiological transport of zinc

The form of zinc that is transported into cells has not yet been identified. The hypothesis that zinc may be transported as a zinc-hisitidine complex has been examined. Uptake of 65-Zn was studied in vitro using rate erythrocytes. Uptake was stimulated by L-histidine (500μM-10mM), but D-histidine inhibited uptake. The effect of L-histidine was sodium-dependent and temperature-dependent, but was DIDS-insensitive. These results are consistent with histidine-linked zinc transport. Another zinc-binding amino acid, L-cysteine, inhibited uptake. Uptake was not affected by L-alanine (100μM-10mM). L-hisitdine also stimulated efflux of 65-Zn from erythrocytes. The distribution of 65-Zn was studied in vivo using rats infused with L-histidine. Infusion for 6 hours (plasma concentrations 2-3.5mM), beginning 48 hours after 65-Zn administration, did not alter activities of 65-Zn in a variety of tissues. However, 65-Zn activity in liver was higher than for control rats. Tissue activity per unit weight (as a proportion of the injected dose) was increased in ileum, skin, bone and muscle from rats injected intravenously during L-histidine infusion. Tissue activity in erythrocytes, liver, spleen and brain was decreased by L-histidine. Infusion of D-histidine produced the same effects. Therefore, these in vivo results do not support the hypothesis of histidine-linked zinc transport. The results show that histidine can affect zinc distribution in animals. However, the mechanism is unclear. Calculation of ionic zinc concentrations in infused rats suggested that ionic zinc transport was not a likely explanation for the in vivo results. It is suggested that some other form of zinc may be transported into tissues. The alteration of zinc status by histidine in humans is discussed, with particular reference to disturbances of zinc physiology during pregnancy.

University of Southampton
Aiken, Simon Piers
Aiken, Simon Piers

Aiken, Simon Piers (1989) Physiological transport of zinc. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The form of zinc that is transported into cells has not yet been identified. The hypothesis that zinc may be transported as a zinc-hisitidine complex has been examined. Uptake of 65-Zn was studied in vitro using rate erythrocytes. Uptake was stimulated by L-histidine (500μM-10mM), but D-histidine inhibited uptake. The effect of L-histidine was sodium-dependent and temperature-dependent, but was DIDS-insensitive. These results are consistent with histidine-linked zinc transport. Another zinc-binding amino acid, L-cysteine, inhibited uptake. Uptake was not affected by L-alanine (100μM-10mM). L-hisitdine also stimulated efflux of 65-Zn from erythrocytes. The distribution of 65-Zn was studied in vivo using rats infused with L-histidine. Infusion for 6 hours (plasma concentrations 2-3.5mM), beginning 48 hours after 65-Zn administration, did not alter activities of 65-Zn in a variety of tissues. However, 65-Zn activity in liver was higher than for control rats. Tissue activity per unit weight (as a proportion of the injected dose) was increased in ileum, skin, bone and muscle from rats injected intravenously during L-histidine infusion. Tissue activity in erythrocytes, liver, spleen and brain was decreased by L-histidine. Infusion of D-histidine produced the same effects. Therefore, these in vivo results do not support the hypothesis of histidine-linked zinc transport. The results show that histidine can affect zinc distribution in animals. However, the mechanism is unclear. Calculation of ionic zinc concentrations in infused rats suggested that ionic zinc transport was not a likely explanation for the in vivo results. It is suggested that some other form of zinc may be transported into tissues. The alteration of zinc status by histidine in humans is discussed, with particular reference to disturbances of zinc physiology during pregnancy.

This record has no associated files available for download.

More information

Published date: 1989

Identifiers

Local EPrints ID: 462698
URI: http://eprints.soton.ac.uk/id/eprint/462698
PURE UUID: 3b9a1d2e-5d6b-484b-9dee-a3b2ec106672

Catalogue record

Date deposited: 04 Jul 2022 19:42
Last modified: 04 Jul 2022 19:42

Export record

Contributors

Author: Simon Piers Aiken

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×