Temperature dependence of the molecular dynamics of platelet membranes in Alzheimer's disease.

The biophysical properties of platelet membranes from five patients with Alzheimer-type dementia and five neurologically healthy controls, matched for age and sex, were examined by fluorescence spectroscopy employing the fluorescent probes DPH and TMADPH. The anisotropy of DPH has previously been observed to be reduced in platelet membranes of patients with Alzheimer-type dementia. However, Alzheimer's disease was not associated with a significant change in the flow activation energy at either deep or superficial regions of platelet membranes. In addition, the temperature-dependent phase transition observed with TMADPH occurred at the same mean temperature in platelet membranes from the demented and control groups.