Abstract

This review discusses recent literature on the chemical and physiological factors that influence the absorption, distribution, and excretion of aluminum in mammals, with particular regard to gastrointestinal absorption and speciation in plasma. Humans encounter aluminum, a ubiquitous yet highly insoluble element in most forms, in foods, drinking water, and pharmaceuticals. Exposure also occurs by inhalation of dust and aerosols, particularly in occupational settings. Absorption from the gut depends largely on pH and the presence of complexing ligands, particularly carboxylic acids, with which the metal can form absorbable neutral aluminum species. Uremic animals and humans experience higher than normal body burdens of aluminum despite increased urinary clearance of the metal. In plasma, 80-90% of aluminum binds to transferrin, an iron-transport protein for which receptors exist in many tissue. The remaining fraction of plasma aluminum takes the form of small-molecule hydroxy species and small complexes with carboxylic acids, phosphate, and, to a much lesser degree, amino acids. Most of these species have not been observed in vivo but are predicted from equilibrium models derived from potentiometric methods and NMR investigations. These models predict that the major small-molecule aluminum species under plasma conditions are charged and hence unavailable for uptake into tissues.

Document Type

Article

Publication Date

11-1994

Notes/Citation Information

Published in Environmental Health Perspectives, v. 102, no. 11, p. 940-951.

EHP is a publication of the U.S. Federal Government, and its content lies in the public domain. No permission is required to reuse EHP content.

This article was reproduced from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1567445/

Funding Information

This work was made possible by EPA Cooperative Agreement 818558.

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