Oral aluminum administration to rats with normal renal function. 2. Body distribution

Tissue response to a supplement high in aluminum and silicon

The objective was to determine the effects of sodium zeolite A (SZA) on mineral metabolism and tissue mineral composition in calves. Twenty calves were placed on study at 3 days of age and were placed into one of two groups: SS, which received 0.05% BW SZA added to their milk replacer, and CO, which received only milk replacer. Blood samples were taken on days 0, 30, and 60 for mineral analysis. Urine and feces were collected on day 30 for mineral metabolism, and on day 60, the calves were euthanized, and samples were taken from numerous organs for mineral analyses. Aluminum retention was increased in the SS calves (p = 0.001). Silicon concentrations were increased in the aorta, spleen, lung, muscle, and kidney of the SS calves, and aluminum was increased in all SS tissues (p < 0.05). Calcium concentrations were increased in aorta, liver, muscle, and tendon; phosphorus concentrations were increased in aorta, but decreased in plasma; magnesium concentrations were increased in aorta, heart, kidney, liver, and pancreas, but decreased in plasma; and iron concentrations were decreased in kidney and liver (p < 0.05). The accumulation of tissue aluminum and therefore potential adverse consequences may preclude any benefits of using SZA as a dietary supplement.

Morphologic and functional alterations of erythroid cells induced by long-term ingestion of aluminium

Anaemia has been associated with aluminium (Al) accumulation in plasma and/or bone tissue in patients with chronic renal insufficiency. Nevertheless, in previous works, we have found shortened red-cell life span, increased osmotic resistance and inhibition of colony-forming units-erythroid (CFU-E) development in Al-overloaded rats with normal renal function. To elucidate further the action of Al on in vivo erythropoiesis, aluminium citrate was provided to Sprague Dawley rats (n = 18) in the drinking water for 8 months. Significant decreases in haematocrit (38.8 +/- 4.29 versus 43.1 +/- 3.58%, p < 0.05) and blood haemoglobin concentration (137 +/- 10.1 versus 148 +/- 8.5 g/l, p < 0.05), reticulocytosis (1.8/1.3-4.2 versus 1.2/0.4-3.7%, p < 0.05), and severe inhibition of CFU-E growth (670/120-950 versus 1530/810-2440 CFU-E/2 x 10(5) cells, p < 0.005) were found. Anysocytosis, poikilocytosis and schistocytosis were detected in peripheral blood stained films. Scanning electron microscopy revealed the presence of erythrocytes with abnormal shape, including crenated and target cells. Aluminium was localised specially inside the schistocytes by EDAX analysis. Decreased haptoglobin concentration (107/83-127 versus 139/89-169 mg/l, p < 0.05) supports the assumption of haemolytic nature of the anaemia. Rats were not iron depleted, as plasma iron concentration and total iron binding capacity were found in the range of control values, and sideroblasts and haemosiderin deposits were observed in bone marrow smears. Total 59Fe uptake and 59Fe incorporated to haem by the bone marrow cells were found decreased. In conclusion, the erythropoiesis impairment induced by Al may be a combined effect of direct action on circulating erythrocytes and interference with the cellular iron metabolism in erythroid progenitors.

Effects of aluminum sulfate on delta-aminolevulinate dehydratase from kidney, brain, and liver of adult mice

The purpose of the present study was to investigate the in vitro and in vivo effects of aluminum sulfate on delta-aminolevulinic acid dehydratase (ALA-D) activity from the brain, liver and kidney of adult mice (Swiss albine). In vitro experiments showed that the aluminum sulfate concentration needed to inhibit the enzyme activity was 1.0-5.0 mM (N = 3) in brain, 4.0-5.0 mM (N = 3) in liver and 0.0-5.0 mM (N = 3) in kidney. The in vivo experiments were performed on three groups for one month: 1) control animals (N = 8); 2) animals treated with 1 g% (34 mM) sodium citrate (N = 8) and 3) animals treated with 1 g% (34 mM) sodium citrate plus 3.3 g% (49.5 mM) aluminum sulfate (N = 8). Exposure to aluminum sulfate in drinking water inhibited ALA-D activity in kidney (23.3 +/- 3.7%, mean +/- SEM, P < 0.05 compared to control), but enhanced it in liver (31.2 +/- 15.0%, mean +/- SEM, P < 0.05). The concentrations of aluminum in the brain, liver and kidney of adult mice were determined by graphite furnace atomic absorption spectrometry. The aluminum concentrations increased significantly in the liver (527 +/- 3.9%, mean +/- SEM, P < 0.05) and kidney (283 +/- 1.7%, mean +/- SEM, P < 0.05) but did not change in the brain of aluminum-exposed mice. One of the most important and striking observations was the increase in hepatic aluminum concentration in the mice treated only with 1 g% sodium citrate (34 mM) (217 +/- 1.5%, mean +/- SEM, P < 0.05 compared to control). These results show that aluminum interferes with delta-aminolevulinate dehydratase activity in vitro and in vivo. The accumulation of this element was in the order: liver > kidney > brain. Furthermore, aluminum had only inhibitory properties in vitro, while in vivo it inhibited or stimulated the enzyme depending on the organ studied.