The chemistry of aluminum as related to biology and medicine.

Martin, R. Bruce

doi:10.1093/clinchem/32.10.1797

Cited by 570 publications

(200 citation statements)

References 0 publications

Supporting

Mentioning

195

Contrasting

Order By: Relevance

“…Saturation values of soluble aluminium hydroxides in a neutral aqueous solution are presumably very low: 8 x 10-6M for Al(OH)and 10-"M for Al(H2O)6+ (MacDonald & Martin, 1988). Several recent publications indicate that the trivalent cation is the biotoxic form of this substance (Martin, 1986;Birchall & Chappell, 1988). Never-g 50o Q.…”

Section: Activity Recordingmentioning

confidence: 99%

Effects of aluminium on electrical and mechanical properties of frog atrial muscle

Meiri

Shimoni

1991

British J Pharmacology

View full text Add to dashboard Cite

The effects of aluminium on membrane ionic currents were studied in single cardiac myocytes. Most of the work was done on frog atrial cells, but some experiments were also carried out on single cells isolated from rabbit ventricles and atria. The effects of aluminium on the force of contraction of frog atrial trabeculae were also investigated. Aluminium was prepared from AlCl3 as a stock 0.5 m solution which has a pH of 3.5. Before each experiment, this solution was added to the control solution, to give a final concentration of 20–100 μg ml−1 aluminium (0.75–3.75 mm AlCl3). The solutions were brought to a pH of 7.4 or 7.6, at which they consist of a mixture of amorphous aluminium hydroxides and a very small amount of soluble ionic aluminium complexes: free aluminium cations (less than 10 pm), aluminohydroxide anions (less than 8 μm). The addition of this suspension reduced the peak inward calcium currents in single rabbit atrial and ventricular cells and in frog atrial cells. In the latter, the peak current was reduced (at + 10 mV) to 45% of control (mean of 9 cells). This effect was reversible upon washout, and was obtained at all membrane potentials, with no shift of the calcium current voltage relationship along the voltage axis. Aluminium also reduced the time‐dependent potassium current IK. This reduction was observed at all membrane potentials. For example, at + 10 mV, the mean reduction of IK (n = 9) was to 69% of the control amplitude. This effect, which was very difficult to reverse, was not due to IK rundown. The fully activated current‐voltage relationships (obtained by standard ‘tail’ analysis) showed that the effect of aluminium was due mainly to a decrease in conductance and not to a shift in the activation range of IK. The mean voltage of half activation was shifted by 8 mV in the depolarizing direction (n = 5). The background potassium current IK1 was also slightly but consistently changed in a complex fashion, with an outward shift at membrane potentials positive to −60 mV. For example, at a membrane potential of −40 mV, the mean shift was by 22 ± 4 pA. At more negative potentials, there was an inward shift in the current amplitudes. For example, for steps to −100 mV the current elicited was larger (more inward) by 53 pA (mean value, n = 10). The reversal potential was slightly shifted (< 10 mV) in the hyperpolarizing direction. The force of contraction of frog atrial trabeculae was altered by aluminium in a complex manner, which showed marked seasonal variation. During most of the year, 50–100 μg ml−1 aluminium caused a biphasic change, with an early small and consistent decrease, followed by a large increase in twitch amplitude. For a short period corresponding to the (local) winter months the sensitivity to aluminium was greatly enhanced. Aluminium 100 μg ml−1 totally abolished contraction (n = 5), while a lower concentration (20 μg ml−1) produced a sustained reduction in the force of contraction. Similar biphasic and seasonal responses have been reported to be induced by lanthanum. The biph...

show abstract

Section: Activity Recordingmentioning

confidence: 99%

Effects of aluminium on electrical and mechanical properties of frog atrial muscle

Meiri

Shimoni

1991

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…A particular problem in the production of homogeneously loaded aluminium standards is the extremely limited solubility of aluminium salts at neutral pH, since at this pH precipitation of AI (OH) 3 occurs. In order to achieve a homogeneous distribution of aluminium it was necessary to use an acidic pH [20]. Preliminary experiments have shown that in aluminium loaded, acidified brain tissue homogenates, a uniform distribution of aluminium was present both in ion images and depth profiles recorded from each homogenate.…”

Section: Discussionmentioning

confidence: 99%

The imaging and quantification of aluminium in the human brain using dynamic secondary ion mass spectrometry (SIMS)

Candy

Oakley

Mountfort

et al. 1992

Biology of the Cell

View full text Add to dashboard Cite

Dynamic secondary ion mass spectrometry (SIMS) has been utilised to study the post-mortem distribution of aluminium in air-dried frozen sections from unfixed, unstained human brain in order to minimise contamination of the tissue and avoid redistribution and extraction of endogenous tissue aluminium. Substrates, sputter-coated with silver, were found to be free of focal aluminum surface contamination and thus minimised substrate induced artefacts in the tissue aluminium ion image. SIMS imaging of aluminium secondary ions at a mass resolution that eliminated the major molecular interferences, combined with a photomontage technique provided a unique strategy for studying aluminium distribution in tissue unrivalled by other spatially resolved microanalytical techniques such as laser microprobe mass spectrometry or X-ray microanalysis. Using this strategy, high densities of focal aluminium accumulations have been demonstrated in the cerebral cortex of the majority of chronic renal dialysis patients studied. In contrast, such aluminium accumulations were absent in control patients. SIMS imaging of aluminium appeared to provide much better discrimination between the dialysis patient group and the control group than one of the most widely used techniques for measuring aluminium in bulk samples, graphite furnace atomic absorption spectrometry. Preliminary studies have shown the feasibility of quantifying focal aluminium SIMS images obtained from brain tissue using aluminium-loaded brain homogenates as reference standards.

show abstract

“…Aluminium salts (sodium and potassium sulphate) have been evaluated by JECFA in 1978(JECFA, 1978 that concluded that the use of aluminium metal as a silvering decoration for certain items of confectionary was not considered to present a health hazard. SALP (E 541) was evaluated by JECFA in 1982, 1985, 1986, 1988, 2006(JECFA, 1982, 1986, 1987, 1989, 2007. In its first evaluation in 1982, a temporary acceptable daily intake (ADI) of 0-6 mg/kg body weight (bw) was allocated due to insufficient data.…”

Section: Information On Existing Authorisations and Evaluationsmentioning

confidence: 99%

Re‐evaluation of aluminium sulphates (E 520–523) and sodium aluminium phosphate (E 541) as food additives

Younes¹,

Aggett²,

Aguilar³

et al. 2018

EFS2

View full text Add to dashboard Cite

The Panel on Food Additives and Nutrient Sources added to Food (ANS) provided a scientific opinion re‐evaluating the safety of aluminium sulphates (E 520–523) and sodium aluminium phosphate, acidic (E 541) as food additives. The Panel considered that adequate exposure and toxicity data were available. Aluminium sulphates (E 520–523) and sodium aluminium phosphate, acidic (E 541) are permitted as food additives in only a few specific products and the exposure is probably near zero. Aluminium compounds have low bioavailability and low acute toxicity. There is no concern with respect to genotoxicity and carcinogenicity. The no observed adverse effect level (NOAEL) for aluminium compounds in subchronic studies was 52 mg Al/kg body weight (bw) per day in rats and 90 mg Al/kg bw per day in dogs and the lowest NOAEL for neurotoxicity in rats was 30 mg Al/kg bw per day and for developing nervous system was 10–42 mg Al/kg bw per day in studies in mice and rats. The Panel concluded that aluminium sulphates (E 520–523) and sodium aluminium phosphate, acidic (E 541) are of no safety concern in the current authorised uses and use levels.

show abstract

The chemistry of aluminum as related to biology and medicine.

Cited by 570 publications

References 0 publications

Effects of aluminium on electrical and mechanical properties of frog atrial muscle

Effects of aluminium on electrical and mechanical properties of frog atrial muscle

The imaging and quantification of aluminium in the human brain using dynamic secondary ion mass spectrometry (SIMS)

Re‐evaluation of aluminium sulphates (E 520–523) and sodium aluminium phosphate (E 541) as food additives

Contact Info

Product

Resources

About