title: Parkinson's disease, L-DOPA, and endogenous morphine: a revisit.
abstract: Clinical observations stemming from widespread employment of restorative L-3,4-dihydroxyphenylalanine (L-DOPA) therapy for management of dyskinesia in Parkinson's Disease (PD) patients implicate a regulatory role for endogenous morphine in central nervous system dopamine neurotransmission. Reciprocally, it appears that restorative L-DOPA administration has provided us with a compelling in vivo pharmacological model for targeting peripheral sites involved in endogenous morphine expression in human subjects. The biological activities underlying endogenous morphine expression and its interaction with its major precursor dopamine strongly suggest that endogenous morphine systems are reciprocally dysregulated in PD. These critical issues are examined from historical and current perspectives within our short review.
authors: Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, NY, USA.
authors: George B
authors: GB
authors: Stefano
authors: Kirk J
authors: KJ
authors: Mantione
authors: Milena
authors: M
authors: Králíčková
authors: Radek
authors: R
authors: Ptacek
authors: Hana
authors: H
authors: Kuzelova
authors: Tobias
authors: T
authors: Esch
authors: Richard M
authors: RM
authors: Kream
mesh_terms: D000818:Animals; D003061:Codeine / Q000652:urine; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D009020:Morphine / Q000096:biosynthesis / Q000378:metabolism* / Q000652:urine; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism* / Q000652:urine; D013765:Tetrahydropapaveroline / Q000652:urine
chemical_list: D007980:Levodopa; D013765:Tetrahydropapaveroline; D009020:Morphine; D003061:Codeine