Plasma glutamate and glycine levels in patients with amyotrophic lateral sclerosis: the effect of riluzole treatment.
OBJECTIVE
Defective glutamate (glu) metabolism and excitotoxicity have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Moreover, glycine (gly) has been shown to potentiate excitatory transmission. The "antiglutamatergic" agent riluzole has been shown to prolong survival in ALS. The aim of the study was to investigate a possible effect of riluzole on plasma glu and gly levels, correlating with clinical response to treatment.


METHODS
Plasma concentrations of glu and gly were measured in 20 healthy volunteers and 22 ALS patients before treatment and after 6 months on riluzole.


RESULTS
At baseline, increased plasma glu correlated with spinal onset and male gender whereas gly levels did not differ between patients and controls. No significant change was observed for both amino acids post-treatment, despite a lower rate of disease progression.


CONCLUSIONS
These results suggest that riluzole may affect disease progression without a significant impact on plasma glu and gly levels, possibly indicating different mechanisms of drug action.
Andreadou
Elisabeth
E
Department of Neurology, Athens National University, Aeginition Hospital, 74, Vas. Sophia's Ave., 11528 Athens, Greece. eandread@med.uoa.gr
Kapaki
Elisabeth
E
Kokotis
Panagiotis
P
Paraskevas
George P
GP
Katsaros
Nikolaos
N
Libitaki
Georgia
G
Zis
Vassilios
V
Sfagos
Constantinos
C
Vassilopoulos
Demetrios
D
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000097:blood* / Q000188:drug therapy*; D002851:Chromatography, High Pressure Liquid; D018450:Disease Progression; D005260:Female; D018698:Glutamic Acid / Q000097:blood*; D005998:Glycine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D019782:Riluzole / Q000627:therapeutic use*; D012727:Sex Characteristics
D018696:Neuroprotective Agents; D018698:Glutamic Acid; D019782:Riluzole; D005998:Glycine