Biological actions of beta-hydroxy-l-glutamic acid, a synthesized structural analogue of glutamic acid.
1. Biological actions of beta-hydroxy-L-glutamic acid (BHGA), a synthesized analog of L-glutamic acid (Glu), were examined using voltage-clamp, electrophysiological and binding assay techniques. 2. Application of BHGA to the voltage-clamped snail neurons elicited an inward current which was blocked by Na(+)-free saline but not by Co(2+)-substituted Ca(2+)-free saline in the voltage-clamped snail neurons. 3. This response exhibited a potency about 10 times stronger than Glu, and was not completely blocked by DL-2-amino-5-phosphonovaleric acid or kynurenic acid. 4. Intraventricular injection of BHGA caused burst discharges in the electrocorticograph (ECoG) of rats whose pattern was similar to that elicited by Glu, but quite different from the ECoG charges induced by NMDA, quisqualic acid, or kainic acid. 5. Receptor binding assays using specific radioactive ligands showed that the binding affinity of BHGA to the Glu receptor was different from that of other agonists tested.
Watanabe
K
K
Department of Physiology, Gifu University School of Medicine, Japan.
Onozuka
M
M
Niwa
M
M
Pongchaidecha
A
A
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology; D004569:Electroencephalography / Q000187:drug effects*; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008566:Membranes / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D017981:Receptors, Neurotransmitter / Q000187:drug effects*; D012908:Snails / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects*
D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D015222:Sodium Channels; D003035:Cobalt; C011859:hydroxyglutamic acid