The glutamate- and glycine-induced reduction of [3H]MK-801 binding in the presence of Mg2+ is reversed at low pH.
At normal pH, glutamate and glycine are known to inhibit [3H]MK-801 binding in the presence of Mg2+. We found, however, that at pH 5.4 glutamate and glycine enhance [3H]MK-801 binding in rat cerebrocortical membranes. Furthermore, H+, similarly to Mg2+, inhibited basal [3H]MK-801 binding. These results indicate that H+ competes with binding sites for Mg2+ and [3H]MK-801, and may be correlated to the depression in neuronal activity observed during acidosis.
Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden.
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von Euler
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Liu
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000378:metabolism*; D004347:Drug Interactions; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005998:Glycine / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D005971:Glutamates; D018698:Glutamic Acid; D016291:Dizocilpine Maleate; D008274:Magnesium; D005998:Glycine