Aluminum chloride does not facilitate deposition of human synthetic amyloid beta1-42 peptide in the rat ventricular system of a short-term infusion model.
Recent data have demonstrated that a 39-43 amino acid peptide called beta-amyloid peptide (Abeta), which predominantly contains 42 residues (Abeta1-42), has a strong tendency to form insoluble aggregates and that the toxic effects of Abeta are based on its aggregation. In a previous study, we reported that infusion of 100 microg of human synthetic Abeta1-42 (sAbeta1-42), which is a main component of diffuse plaques, into the lateral ventricle of the rat brain of a short-term infusion model resulted in almost complete disappearance of sAbeta1-42 aggregates from the ventricles by 28 days. In addition, aluminum is considered a potential etiological factor in Alzheimer's disease (AD). Neurotoxicity from excess brain exposure to aluminum has been documented from both clinical observations and animal experiments, although a direct relationship between aluminum and AD has yet to be clearly established. We therefore investigated the effects of sAbeta1-42 aggregates with aluminum chloride (AlCl3) in the ventricular system of the rat brain of a short-term infusion model. At either 2 or 7 days following infusion, sAbeta1-42 formed aggregates with AlCl3 that spread throughout the entire ventricular system. However, sAbeta1-42 aggregates with AlCl3 had almost disappeared from the ventricles by 28 days, resulting in similarities with respect to the time-course and the neuropathological changes observed in sAbeta1-42 aggregation without AlCl3. We herein report for the first time that considerable amounts of sAbeta1-42 aggregates with AlCl3 almost disappear from the rat ventricular system by 28 days post-infusion.