Biphasic effects of magnesium on the [3H]N-(1-(2-thienyl)cyclohexyl)-3,4-piperidine binding in the rat cerebral cortex.
Mg2+ at micromolar concentrations greatly enhanced [3H]N-(1-(2-thienyl)cyclohexyl)-3,4-piperidine ([3H]TCP) binding to well-washed rat cortical membranes, whereas [3H]TCP binding was inhibited by Mg2+ at concentrations higher than 1 mM. In the presence of either L-glutamate (10 microM) or glycine (10 microM), 30 microM Mg2+ caused further stimulation of [3H]TCP binding, suggesting that a high-affinity site for Mg2+ is distinct from the glutamate or glycine binding site. These findings indicate that Mg2+ acts on at least two different recognition sites, e.g. a novel high-affinity site for Mg2+ which stimulates [3H]TCP binding and the Mg2+ recognition site located within the ion channel.
Hori
T
T
Department of Psychopharmacology, Psychiatric Research Institute of Tokyo, Japan.
Yamamoto
T
T
Hatta
K
K
Moroji
T
T
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005998:Glycine / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D010622:Phencyclidine / Q000031:analogs & derivatives* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014316:Tritium
D005971:Glutamates; D014316:Tritium; D018698:Glutamic Acid; C012058:tenocyclidine; D008274:Magnesium; D010622:Phencyclidine; D005998:Glycine