CYTOSOLIC-FREE [CA2-CELLS FROM DEMENTED PATIENTS AND HEALTHY CONTROLS(] IN MONONUCLEAR BLOOD)

There is increasing evidence that the neurodegenerative processes in A lzheimer's disease (AD) may be related to alterations in calcium homeo stasis and that these metabolic changes are not necessarily restricted to the central nervous system. However, previous studies investigatin g [Ca2+](i) in fibroblasts, lymphoblasts, platelets and lymphocytes of AD patients gave inconclusive results, since increase, decrease and n o alteration in [Ca2+](i) were found in AD patients compared with cont rols. With respect to the importance of establishing altered Ca2+ home ostasis in peripheral cells, we have investigated [Ca2+](i) in circula ting mononuclear cells of patients with AD, multi-infarct dementia, ag e-associated memory impairment and healthy controls. [Ca2+](i) was eva luated using the fluorescent dye fura-2 before and during stimulation with phythaemagglutinin (PHA). In our study we failed to find major di fferences in resting [Ca2+](i) and in response to stimulation with 25 mu g/ml and 100 mu g/ml PHA in cells of AD patients as compared with a ll other groups investigated. There was only a tendency towards a decr ease in [Ca2+](i) in AD after stimulation with PHA. Thus the pre sent findings suggest that [Ca2+](i) evaluation in mononuclear cells does n ot have diagnostic value in discriminating AD patients from other deme nted patients. However, there might be some difference in [Ca2+](i) va lues between early- and late-onset AD, which could have pathophysiolog ical importance.