title: The convulsant drugs 3-mercaptopropionate and methionine sulfoximine inhibit L-glutamate and L-aspartate binding to a hydrophobic protein fraction from rat cerebral cortex.
abstract: The action of the convulsant drugs, methionine sulfoximine (MSO), 3-mercaptopropionate (3-MP), megimide (MG), and allylglycine on the binding of L-[14C]aspartate, L-[14C]glutamate and [14C]GABA to a hydrophobic protein fraction isolated from rat cerebral cortex was studied. Using the convulsant at 10(-4) M concentration and the radioactive ligands as 10(-6) M the binding of L-[14C]glutamate was inhibited 60% by 3-MP and 40% by MSO, while MG and allylglycine had no effect. The binding of L-[14C]aspartate was inhibited 55%, and 10--20% by 3-MP and MSO, respectively, while MG and allylglycine had not effect. None of the drugs mentioned, except for a minimal inhibition by MG, altered the binding of [14C]GABA. Neither MSO nor 3-MP affected the high-affinity sites for L-[14C]glutamate of L-[14C]aspartate, but they had a strong inhibitory action on the medium affinity site. These results are discussed in relation to the possible mechanism of action of these drugs on L-glutamate and L-aspartate receptors.
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000494:pharmacology*; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D008717:Methionine Sulfoximine / Q000494:pharmacology*; D011510:Proteolipids / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D013438:Sulfhydryl Compounds
chemical_list: D005971:Glutamates; D011510:Proteolipids; D013438:Sulfhydryl Compounds; D008717:Methionine Sulfoximine; D001224:Aspartic Acid; D015097:3-Mercaptopropionic Acid