PLATELET MEMBRANE PROPERTIES IN ALZHEIMER AND MULTI-INFARCT DEMENTIAS

Abstract

Recent investigations revealed that the physical properties of both central andperipheral cell membranes are changed in dementia of the Alzheimer Type (DAT). Weattempted to ascertain whether this effect is specific for DAT by studying the polarization ofdiphenylhexatriene (DPH) fluorescence (an indicator of membrane “microviscosity”) in themembranes of platelets isolated from DAT patients, patients with multi-infarct dementiaand healthy controls. The 3 groups were matched as closely as possible for age and sexdistributions. Platelet phospholipid composition was also examined in an attempt to identifythe chemical basis of the membrane change(s) These studies revealed that DPH fluorescence polarization is significantly reduced in plate-lets from DAT patients, but not in patients with multi-infarct dementia, compared withcontrols. Analysis of the phospholipid composition of platelets from the 3 groups of subjectsdid not find any significant differences which might explain the change in membrane properties.