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Accumulation of dopamine by blood platelets from normal subjects and parkinsonian patients under treatment with l ‐DOPA
Author(s) -
BOULLIN D. J.,
O'BRIEN R. A.
Publication year - 1970
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1970.tb09904.x
Subject(s) - dopamine , platelet , dopaminergic , endocrinology , medicine , levodopa , incubation , chemistry , endogeny , parkinson's disease , biochemistry , disease
Summary1 Human blood platelets have been shown to take up dopamine by an energy‐dependent, saturable process that is inhibited by 5‐hydroxytryptamine (5‐HT), desipramine and other drugs. 2 Platelets from parkinsonian subjects receiving oral l ‐DOPA also took up dopamine. 3 When the responses of normal and parkinsonian platelets were compared, the parkinsonian cells showed the following differences: increased affinity for the dopamine transport process; decreased equilibrium concentrations of dopamine after incubation for 90 min, and greater efflux of dopamine from loaded platelets during a 10 min incubation. 4 There were no differences in the uptake of 5‐HT by parkinsonian platelets, but endogenous 5‐HT was significantly reduced; ATP was normal. 5 In two out of three samples of platelets from parkinsonian subjects, traces of a dopamine‐like substance were detected, but this finding requires confirmation. 6 If the platelet is a valid model for dopaminergic brain neurones, then the results described would suggest that dopamine uptake and storage may be abnormal in brain neurones in Parkinson's disease.