Abstract
The calcium hypothesis of neurodegenerative disorders such as Alzheimer's disease (AD) states that altered cytosolic Ca2+ levels ( Ca2+ i) and/or disturbances in Ca2+ homeostasis are the cellular mechanisms underlying neuronal pathology. To search for a diagnostic marker of Alzheimer's disease (AD), we measured cytosolic calcium concentration ([Ca2+]i) in platelets of AD patients, age-matched control subjects (AMC), and vascular dementia (VD) patients.
The ( Ca2+ i) was determined using long wavelength indicator Fluo-3AM in 21 mild AD patients, 17 AMC, and 23 patients with VD. The basal values of [Ca2+]i were significantly lower in AD compared to AMC.
After the addition of 1 mM calcium, the [Ca2+]i markedly increased in platelets of AD compared to AMC and VD. Measurement of calcium homeostasis could provide a very sensitive, but less specific biological marker of AD.
These results support the hypothesis that influencing calcium homeostasis may offer a therapeutic strategy in dementia.