title: L-glutamate, L-arginine and L-citrulline levels in cerebrospinal fluid of Parkinson's disease, multiple system atrophy, and Alzheimer's disease patients.
abstract: Alterations in neuronal nitric oxide (NO) production may play a role in the pathophysiology of Parkinson's disease (PD) Alzheimer's disease (AD), and multiple system atrophy (MSA). The biosynthesis of NO is dependent on the availability of L-arginine, the substrate for NO-synthase (NOS), and on L-glutamate, which stimulates NO synthesis via the NMDA receptor. In this process L-citrulline is formed. We measured the levels of these amino acids in cerebrospinal fluid (CSF) of 108 PD patients, 12 AD patients, 15 MSA patients and 21 healthy subjects. A slight but statistically significant elevation of CSF L-citrulline was found in MSA patients, while CSF L-glutamate was found to be significantly decreased in AD patients. We found no significant changes in L-arginine levels. Although the relation between the CSF levels of these amino acids and neuronal NO production is still unclear, our findings suggest that AD is associated with a decrease in NO synthesis.
authors.affiliation: Department of Neurology, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Kuiper
authors.forename: T
authors.initials: T
authors.lastname: Teerlink
authors.forename: J J
authors.initials: JJ
authors.lastname: Visser
authors.forename: P L
authors.initials: PL
authors.lastname: Bergmans
authors.forename: P
authors.initials: P
authors.lastname: Scheltens
authors.forename: E C
authors.initials: EC
authors.lastname: Wolters
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D001120:Arginine / Q000134:cerebrospinal fluid*; D002956:Citrulline / Q000134:cerebrospinal fluid*; D018698:Glutamic Acid / Q000134:cerebrospinal fluid*; D006801:Humans; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010300:Parkinson Disease / Q000134:cerebrospinal fluid* / Q000503:physiopathology
chemical_list: D002956:Citrulline; D009569:Nitric Oxide; D018698:Glutamic Acid; D001120:Arginine; D019001:Nitric Oxide Synthase