L-[35S]cysteic acid selectively detects chloride-dependent L-glutamate transporters in synaptic membrane.
Na+-independent L-[35S]cysteic acid (CA) accumulation in rat cortical synaptic membrane was examined. In the absence of Cl-, the accumulation was not observed. Addition of Cl- revealed the accumulation in a dose-dependent manner. Br- and NO3- also did. Ca2+-enhanced the Cl- -dependent accumulation, whereas low concentrations of Na+ reduced it. L-[35S]CA accumulation was inhibited by quisqualate, L-glutamate (L-Glu), L-cysteine sulfinate, D,L-homocysteic acid and D,L-2-amino-4-phosphonobutyrate (D,L-APB) potently. L-CA inhibited L-[3H]Glu accumulation in synaptic membrane in the presence of Cl-. The maximal inhibition of L-CA was equal to that of D,L-APB, but L-CA did not inhibit L-[3H]Glu accumulation in the absence of Cl-. These results show that L-[35S]CA selectively detects the Cl- -dependent L-Glu transporters in synaptic membrane.
Koyama
Y
Y
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Osaka University, Suita, Japan.
Baba
A
A
Iwata
H
H
D000603:Amino Acids, Sulfur / Q000493:pharmacokinetics*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002712:Chlorides / Q000502:physiology*; D003544:Cysteic Acid / Q000493:pharmacokinetics*; D005971:Glutamates / Q000493:pharmacokinetics*; D018698:Glutamic Acid; D008297:Male; D010069:Oxadiazoles / Q000494:pharmacology; D016318:Quisqualic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D000603:Amino Acids, Sulfur; D002352:Carrier Proteins; D002712:Chlorides; D005971:Glutamates; D010069:Oxadiazoles; D018698:Glutamic Acid; D016318:Quisqualic Acid; D003544:Cysteic Acid; D002118:Calcium