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BIOLOGICAL SPECIATION AND TOXICOKINETICS OF ALUMINUM
Citation:
DeVito, E. AND R. Yokel. BIOLOGICAL SPECIATION AND TOXICOKINETICS OF ALUMINUM. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-95/356.
Description:
This review discusses recent literature on the chemical and physiological factors that result in the absorption, distribution, and excretion of aluminum in mammals, with particular regard to gastrointestinal absorption and speciation in plasma. umans encounter aluminum, a ubiquitous yet highly insoluble element in most forms, in foods, drinking water, and pharmaceuticals and, by inhalation, in dust and aerosols, particularly in occupational settings. bsorption from the gut depends largely on pH and the presence of completing ligans, particularly carboxylic acids, with which the metal can form absorbable neutral aluminum species. remic animals and humans attain higher-than-normal body burdens of aluminum despite increased urinary clearance of the metal. n plasma, 80-90% of aluminum binds to transferrin, an iron-transport protein for which receptors exist in many tissues. he remaining fraction of plasma aluminum takes the form of small molecule hydroxy species ad small complexes with carboxylic acids, phosphate, and, to a lesser degree, amino acids. ost of these species have not been observed in vivo but are predicted from equilibrium models derived from potentiometric methods and NMR investigations. hese models predict that the major small molecule aluminum species under plasma conditions are uncharged and, hence, unavailable for uptake into tissues.