Alterations in Calcium Homeostasis as Biological Marker for Mild Alzheimer´s Disease?

D. ŘÍPOVÁ¹, V. PLATILOVÁ¹, A. STRUNECKÁ², R. JIRÁK³, C. HÖSCHL<sup>1,4

1</sup>Laboratory of Biochemistry, Prague Psychiatric Center, ²Department of Physiology and Developmental Biology, Faculty of Sciences, Charles University, ³Psychiatric Clinic of the First Medical Faculty, Charles University and ⁴Third Medical Faculty, Charles University, Prague, Czech Republic

Received May 5, 2003
Accepted September 15, 2003



Summary
The calcium hypothesis of neurodegenerative disorders such as Alzheimer´s disease (AD) suggests that altered cytosolic Ca²⁺ levels ([Ca²⁺]_i) and/or disturbances in Ca²⁺ homeostasis concern cellular mechanisms underlying neuronal pathology. To search for a diagnostic marker of Alzheimer´s disease, we measured cytosolic calcium concentrations 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 provide a therapeutic strategy in dementia.


Key words
Alzheimer´s disease • Vascular dementia • Platelets • Calcium homeostasis • Biological marker