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Inhibition of GABA B Receptor Binding by Guanyl Nucleotides
Author(s) -
Hill D. R.,
Bowery N. G.,
Hudson A. L.
Publication year - 1984
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1984.tb02732.x
Subject(s) - gtp' , gabab receptor , adenylate kinase , receptor , chemistry , aminobutyric acid , nucleotide , cyclase , biochemistry , g protein , binding site , gabaa receptor , enzyme , gene
GTP and GDP decreased the saturable binding of [ 3 H]baclofen or [ 3 H]γ‐aminobutyric acid ([ 3 H]GABA) to GABA B but not GABA A receptors whereas GMP displayed negligible activity. This effect was specific to guanyl nucleotides and was not mimicked by high concentrations of ATP. The inhibition of ligand binding was the result of a diminished receptor affinity with no change in receptor number. The use of a complete physiological saline solution rather than Tris buffer plus Ca 2+ or Mg 2+ increased the potency of GTP at the GABA B receptor. The results are discussed in relation to the effects of GABA and GTP on adenylate cyclase activity in the brain.