Tissue turnover of aluminum and Ga-67: Effect of iron status

The purposes of this study were to evaluate the effect of nutritional status in regard to iron on aluminum distribution and turnover and to evaluate Ga-67 as a marker for aluminum. Anemic (n = 27) and normal (n = 30) rats were dosed by gavage with 0.8 mmoles of aluminum and 20 μCi Ga-67 in a 0.75 mol/l citrate solution and sacrificed 1, 3, 6, 9, 15, and 21 days later. Anemic rats generally retained more aluminum in their livers but less in tibias and spleens than normal rats. The half-lives of aluminum in liver (56 vs 17 days), muscle (33 vs 16 days), and serum (12 vs 8 days) were significantly greater in anemic than normal rats, respectively. Total body retention of Ga-67 could be described on the basis of a two-compartment model. The turnover of Ga-67 from the first compartment was rapid (half-life = 0.8 and 0.6 days) in anemic and normal rats, respectively, and was similar to the turnover of Ga-67 from the GI tract (half-life = 0.7 and 0.6 days in anemic and normal rats, respectively). The turnover of Ga-67 from the second compartment was also rapid (2.8 vs 4.0 days in anemic and normal rats, respectively). Anemia affected the retention of Ga-67 more than the retention of aluminum; anemic rats retained more Ga-67 in their livers, spleens, kidneys, hearts, and muscles but less in their tibias than normal rats. In general, Ga-67 was not a satisfactory marker for aluminum distribution and turnover in normal and anemic rats.