Abstract
Alterations in calcium homeostasis might be implicated in the neuropathology of Alzheimer's disease (AD). To date it is not clear whether changes in cytosolic calcium level ([Ca2+](i)) are the result or the cause of pathogenic effects.
In platelets of patients with early stages of AD, the basal values of [Ca2+](i) in the absence of extracellular Ca2+ were significantly lower in comparison with age-matched and young controls. After the addition of 1 mM calcium into the incubation medium the [Ca2+](i) markedly increased in platelets of AD patients whereas the increase only to a smaller extent was observed in control age-matched and young subjects.
The present study proposes that calcium dysregulation during the whole disease period could not be uniform and according to our results the [Ca2+](i) is reduced in the first stages of AD. We suggest that the disturbed calcium homeostasis in AD is an "early defect."