Genetic influences on tissue deposition of aluminum in mice

Aluminum is a known neurotoxin and has been suggested to play a role in the development of Senile Dementia of the Alzheimer's Type. The relationship between aluminum exposure and senile dementia cannot be a simple one, however, as not all exposure results in neurotoxic manifestations. To determine if there are genetic differences in susceptibility to moderate aluminum exposure, 16 mice of five inbred strains were divided into two groups. The control group was fed a purified diet containing all known requirements for mice; the experimental group was fed the same diet supplemented with 260 mg Al/kg diet for 28 d. Analysis of brains, livers, and tibias for aluminum concentrations revealed strain differences in response to dietary treatment. The most notable results occurred in the DBA/2 and C3H/2 strains, with brain aluminum levels higher in the experimental groups. In contrast, A/J, BALB/c, and C57BL/6 strains showed no differences in brain aluminum in response to dietary treatment. These findings suggest that there are genetic differences in the permeability of the blood brain barrier and lend support to the hypothesis that variability in aluminum toxicity may be, in part, genetically determined.