The bioavailability of26Al-labelled aluminium citrate and aluminium hydroxide in volunteers

Abstract

A study was undertaken to determine the fraction of ingested aluminium taken up by two male volunteers, following their ingestion of either aluminium citrate or aluminium hydroxide. In addition, the effects of simultaneous citrate ingestion on the gastrointestinal absorption of aluminium from its hydroxide was studied. Volunteers received three oral doses of 26Al-labelled aluminium compound in water. The doses were administered directly into the stomach using a paediatric feeding tube. Blood samples were collected from the volunteers at 1, 4 and 24 h after administration, and their daily output of urine and faeces was collected for 6 days. These samples were analysed for their 26Al content using either coincidence gamma-counting or accelerator mass spectrometry. The uptake of aluminium was greatest following its administration in the citrate form and was least following intake as the aluminium hydroxide suspension. The co-administration of citrate, with the aluminium hydroxide suspension, was found to enhance the levels of 26Al uptake in both volunteers. Using a urinary excretion factor based on the results of previous studies, the fractional aluminium uptake from each of the species was calculated: aluminium citrate, 5.23 x 10(-3); aluminium hydroxide, 1.04 x 10(-4); aluminium hydroxide with citrate, 1.36 x 10(-3).

Al-toxicity studies in yeast using gallium as an aluminum analogue

“…67 Gallium as a tracer for Aluminum 67 Ga is readily available because it is used in routine clinical diagnoses (Priest et al 1995(Priest et al , 1996Radunovic et al 1997a, b). It is a cheap and readily available isotope in Australia (ANSTO, Lucas Heights, NSW) and elsewhere.…”

“…A few clinical studies have attempted to measure Al uptake using 26 Al in mammalian systems (humans: Priest et al 1995Priest et al , 1996mice: Radunovic et al 1997a;rats: Radunovic et al 1997b;Zafar et al 1997, review: Gupta et al 2005. Some of these studies attempted to use 67 Ga as a tracer for Al Biometals (2008) 21:379-393 381 and had the resources to be able to do 26 Al/ 67 Ga double labelling experiments.…”

“…It is available only at very low specific activity, making it difficult to count using a c-ray or scintillation counter even though it emits c and b radiation that would otherwise make it a simple radiotracer to count. Exceptionally, Priest et al (1995Priest et al ( , 1996 had access to enough 26 Al to be able to use a c-ray counter to count blood samples. Taylor et al (2000) were able to obtain enough 26 Al to use it as a tracer for Al uptake by the giantcelled alga, Chara.…”

Aluminium: Food-related health risk assessment of the consumers

“…A number of researches have shown that aluminium intake with drinking water can make for dementia evolvement and Alzheimer syndrome [9,8,34,35]. Such effect can be explained by the fact that aluminium salts contribute to inflammatory cytokine activation in cerebrum [12].…”

Accelerator Mass Spectrometry as a Bioanalytical Tool for Nutritional Research

“…The biological effects of this active chemical element in humans is currently being studied using 26Al, whose 750,000 year half life is more amenable to biological experimentation that the next longest lived isotope at 6.5 minutes: 29Al. (Barker et al 1992;Day et al 1994;Harris et al 1996;Jouhanneau et al 1993;Priest et al 1995;Priest et al 1996) Kislinger et al 1997;Steinhausen et al 1996).…”