Disruption of zinc homeostasis in Alzheimer's disease

The basic hypothesis being tested is that, in Alzheimer's disease (AD), the delicate balance of brain Zn is disrupted and may play a role in the pathogenesis of neuron degeneration. Micro-PIXE measurements reveal a significant elevation of Zn in senile plaques (SP) in AD brain compared with adjacent neuropil and a significant increase in AD neuropil compared to control neuropil. The observation of elevated Zn in SP is of interest because the amyloid precursor protein contains a Zn binding site that may prevent normal cleavage leading to the generation of a toxic fragment of beta amyloid, the constituent of SP, The potential of using laser-ablation inductively coupled plasma mass spectrometry as a complimentary microprobe technique is also presented. (C) 2002 Elsevier Science B.V. All rights reserved.