Possible Interaction: Aspartate and Glutamate

“Uptake of 0.2 microM L-glutamate was inhibited by 2 mM L-glutamate, L-aspartate , D-aspartate, L-cysteate, and L-cysteinesulfinic acid and was uninhibited by 2 mM D-glutamate, L-glutamine, L-alanine, L-serine, L-asparagine, and taurine or by 1 mM methylaminoisobutyric acid.”

“Uptake of L-glutamate into sarcolemmal vesicles was inhibited by L-aspartate and L-cysteinate.”

“ L-Glutamate and D-aspartate, but not D-glutamate, were found to inhibit L-aspartate influx , suggesting that this uptake system has a substrate specificity similar to that previously described for a high-affinity (Km = 16 microM) acidic amino acid transporter in the same cells.”

“The role of L-aspartate as the transmitter in CNS is not clear but its contribution may be less than that of L-glutamate.”

“The potency of L-aspartate in exciting Purkinje cells was lower than that of L-glutamate when the two drugs were released from adjacent barrels of the same iontophoretic electrode.”

“ L-Aspartate and L-glutamate caused a significant increase of neuronal cell firing, the effects were dose-related, reversible and reproducible.”

“ L-Glutamate was the most potent amino donor, and L-aspartate strongly inhibited the reaction.”

“From these and other results one concludes that: (a) [3H]GABA release from H1 cells is calcium independent …) the likely transmitter of red cones is L-Glu acting on quisqualate or kainate receptors, and (3) L-Asp acts predominantly on NMDA receptors … by potentiating the action of L-Glu.”

“The main findings are: (1) virtually all of the [3H]GABA released by L-glutamate (L-Glu) and L-aspartate (L-Asp) and … potentiates the action of L-Glu by 0.6-0.8 log units and completely inhibits the action of L-Asp; (7) L-Asp … L-Glu.”

“Thus, although L-glutamate and L-aspartate are believed to share a common transport system, it appears that transport of these two excitatory amino acids may be differentially regulated.”

“The amino acid L-aspartate markedly potentiates the responses elicited by L-glutamate at excitatory neuromuscular synapses in lobster walking limbs.”