Effect of diphenylthiocarbazone (dithizone) on glutamate level in hippocampus preparation in vitro and in vivo.
To assess the functional interaction between Zn2+ and glutamate in hippocampus, diphenylthiocarbazone (dithizone), a Zn2+ chelator, was used to alter the glutamate level in hippocampus in vitro and in vivo. Dithizone at the concentration of 1 microM stimulated high K(+)- and veratrine-induced release of [3H]glutamate both in the presence and absence of Ca2+ from rat hippocampal slices preloaded with [3H]glutamate without affecting the release of [3H]gamma-aminobutyric acid and [3H]acetylcholine. Metal chelators other than dithizone did not evoke the [3H]glutamate release at the concentration of 10 microM. Two weeks after the intrahippocampal injection of 20 micrograms of dithizone, both Zn2+ and glutamate levels of the hippocampus significantly decreased with no change in the levels of other metals, amino acids, monoamines and acetylcholine.
Kihara
T
T
Laboratory of Molecular Pharmacology, Suntory Institute for Biomedical Research, Osaka, Japan.
Ishihara
T
T
Baba
A
A
Iwata
H
H
D000109:Acetylcholine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D015306:Biogenic Monoamines / Q000378:metabolism; D004230:Dithizone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005971:Glutamates / Q000378:metabolism*; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism*; D008297:Male; D008670:Metals / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014316:Tritium
D000596:Amino Acids; D001391:Azo Compounds; D015306:Biogenic Monoamines; D005971:Glutamates; D008670:Metals; D014316:Tritium; D004230:Dithizone; D000109:Acetylcholine