Effects of aluminium on the mineral metabolism of rats in relation to age

Abstract

The present study was conducted to assess in rats the effects of chronic aluminium (Al) exposure on calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), zinc (Zn) and iron (Fe) accumulation and urinary excretion in relation to the age of the animals. Male young (21 day old), adult (8 months), and old (16 months) rats were orally exposed to 0, 50, or 100 mg Al/kg/day for a period of 6.5 months. Urinary levels of essential elements were determined after 3 and 6.5 months of exposure, whereas tissue Ca, Mg, Mn, Cu, Zn and Fe concentrations were examined after 6.5 months of Al administration. A number of age-related changes in tissue accumulation and urinary excretion of essential elements following chronic exposure to Al were found. Concentrations of essential elements in most tissues of young Al-exposed rats were generally lower than those of adult and old rats. The highest levels of essential elements were found in old animals. Liver, testes and spleen were the tissues that showed the most remarkable increases in relation to the levels found in those tissues of young rats. Adult rats showed a pattern comparable to that of old animals for mineral metabolism in brain, whereas in bone and testes the pattern of accumulation was closer to that of young rats. While the urinary levels of Ca were generally reduced in the Al-exposed groups, no Al-associated changes were noted for Mg, Mn, Cu and Zn. In turn, after 6.5 months of Al administration Fe excretion was increased in Al-treated adult and old rats. The results of this study suggest that early stages of life cycle should be of special concern for Al-induced changes in the metabolism of essential elements.