The neuroregulatory properties of L-DOPA. A review of the evidence and potential role in the treatment of Parkinson's disease.
Accumulating evidence suggests that L-dihydroxyphenylalanine (L-DOPA) has neurotransmitter-like and/or neuromodulatory properties in the CNS. Such evidence is based on a wide range of findings including the existence of specific L-DOPAergic neurons in several regions of the CNS, neurotransmitter-like characteristics and specific pharmacological effects. This review attempts to outline the main evidence for this conception and to relate such findings to L-DOPA treatment effects in Parkinson's disease. In this context L-DOPA in itself has been shown to potentiate D2 receptor-mediated effects, inhibit acetylcholine release and increase the release of L-glutamate, neuropharmacological effects which can be linked to treatment side-effects in advanced Parkinson's disease. It is suggested that supersensitive L-DOPA-mediated effects contribute to the pathogenesis underlying L-DOPA-induced motor complications in advanced Parkinson's disease. However, since specific L-DOPA receptors have yet to be identified, the assessment of the relative importance of L-DOPA-mediated effects in this clinical context must be regarded as incomplete.
Tedroff
J M
JM
Department of Neurology, University Hospital, Uppsala, Sweden.
D002490:Central Nervous System / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D007980:Levodopa / Q000378:metabolism / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D017981:Receptors, Neurotransmitter / Q000378:metabolism
D017981:Receptors, Neurotransmitter; C087658:levodopa receptor; D007980:Levodopa