MONOAMINE-OXIDASE MOLECULAR ACTIVITY IN PLATELETS OF PARKINSONIAN ANDDEMENTED PATIENTS

Platelet monoamine oxidase activity levels have been evaluated in seve ral neuropsychiatric disorders, to identify biochemical markers for pa thological brain functioning. In the present work, we assayed both tot al and molecular monoamine oxidase activity in platelets of parkinsoni an and demented patients: both showed significantly higher enzyme acti vity values than healthy controls. Thus, high platelet monoamine oxida se activity levels seem to be related to an increased intrinsic activi ty of single enzyme molecules. A significant positive correlation was found between platelet monoamine oxidase activity and severity of illn ess in both disorders: monoamine oxidase activity, therefore, may be c onsidered as a state-dependent marker for neurodegeneration. Such find ings are discussed with reference to central nervous system biochemica l abnormalities in parkinsonian and demented subjects; it might be tha t in both Parkinson's Disease and in dementia of Alzheimer type some c entral biochemical changes are reflected in certain peripheral tissues (thrombocytes, for instance), or that a systemic derangement accompan ies the cerebral involvement. (C) 1996 Academic Press Limited