Effect of aspartame on N-methyl-D-aspartate-sensitive L-[3H]glutamate binding sites in rat brain synaptic membranes.
Aspartame (L-aspartyl-L-phenylalanine methyl ester), an artificial low-calorie sweetener, was shown to dose-dependently inhibit L-[3H]glutamate binding to its N-methyl-D-aspartate-specific receptors. L-Aspartic acid, a major endogenous metabolite of aspartame, inhibited the binding more stronger than aspartame, while the other metabolites, L-phenylalanine and methanol, had no effect at the same concentration. Aspartame caused a significant change in the affinities of L-[3H]glutamate binding without altering the Vmax values of the binding, suggesting the inhibition is competitive. These in vitro findings suggested that aspartame may act directly on the N-methyl-D-aspartate-sensitive glutamate recognition sites in the brain synaptic membranes.
Pan-Hou
H
H
Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
Suda
Y
Y
Ohe
Y
Y
Sumi
M
M
Yoshioka
M
M
D000818:Animals; D001218:Aspartame / Q000494:pharmacology*; D001224:Aspartic Acid / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D004151:Dipeptides / Q000494:pharmacology; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D007700:Kinetics; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D010649:Phenylalanine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D013570:Synaptic Membranes / Q000187:drug effects / Q000378:metabolism*
D004151:Dipeptides; D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; D001224:Aspartic Acid; D018698:Glutamic Acid; D010649:Phenylalanine; D016202:N-Methylaspartate; D001218:Aspartame