L(+)-2-amino-4-phosphonobutyrate inhibits the release of both glutamate and dynorphin from guinea pig but not rat hippocampal mossy fiber synaptosomes.
The K+-evoked release of dynorphin A(1-8)-like immunoreactivity from guinea pig hippocampal mossy fiber synaptosomes was inhibited 53% by L(+)-2-amino-4-phosphonobutyrate (L(+)APB, 300 microM), a glutamate analogue. Equimolar L(+)APB also inhibited the Ca2+-dependent component of endogenous L-glutamate release from these mossy fiber synaptosomes by 40%. The K+-evoked release of both glutamate and dynorphin A(1-8) from rat hippocampal mossy fiber synaptosomes were unaffected by L(+)APB. It is proposed that L(+)APB selectively suppresses the excitatory mossy fiber synaptic inhibiting the Ca2+-dependent release of glutamate and dynorphin A(1-8) from guinea pig but not rat hippocampal mossy fiber terminals.
Gannon
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RL
Clinical Sciences Division, USAF School of Aerospace Medicine, Brooks AFB, TX 78235-5301.
Baty
L T
LT
Terrian
D M
DM
D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D004399:Dynorphins / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D000613:Aminobutyrates; D005971:Glutamates; D010446:Peptide Fragments; D018698:Glutamic Acid; D004399:Dynorphins; C026770:dynorphin (1-8); C012729:2-amino-4-phosphonobutyric acid