Platelet phenolsulphotransferase activity in patients with dementia of Alzheimer type

Human blood platelets are more and more regarded as a reliable model of nerve cells, and some biochemical alterations found in platelet enzyme activities and receptor binding parameters may be related to analogous changes occuring in the central nervous system. Platelet phenol-sulphotransferase activity has been evaluated in some neurological disorders, such as Parkinson's disease and headache. In the present work we determined phenolsulphotransferase activity in platelets of 36 patients with dementia of Alzheimer type, and compared such activity values with those of 36 sex- and age-matched healthy controls. Patients showed a significantly higher platelet phenolsulphotransferase activity than control subjects, both with dopamine and with phenol as substrates. Moreover, a significant positive correlation was found between platelet enzyme activity and severity of illness. These findings are discussed in terms of the biochemical abnormalities found in the central nervous system of demented subjects, and in terms of the possible pathogenetic involvement of an altered phenolsulphotransferase activity (and, in general, of a modified monoamine metabolism) in such derangements of biochemical systems often occuring in dementia of Alzheimer type.