Abstract
The R- and S-enantiomers of 4-amino-3-hydroxybutanoic acid (GABOB) were full agonists at human recombinant rho1 GABA(C) receptors. Their enantioselectivity (R>S) matched that reported for their agonist actions at GABA(B) receptors, but was the opposite to that reported at GABA(A) receptors (S>R). The corresponding methylphosphinic acid analogues proved to be rho1 GABA(C) receptor antagonists with R(+)-CGP44533 being more potent than S(-)-CGP44532, thus showing the opposite enantioselectivity to the agonists R(-)- and S(+)-GABOB. These studies highlight the different stereochemical requirements for the hydroxy group in these analogues at GABA(A), GABA(B) and GABA(C) receptors.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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GABA Agonists / chemistry
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GABA Agonists / pharmacology*
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GABA Antagonists / chemistry
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GABA Antagonists / pharmacology
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Humans
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Hydrogen Bonding
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Phosphinic Acids / chemistry
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Phosphinic Acids / pharmacology
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Receptors, GABA / chemistry
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Receptors, GABA / drug effects*
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Receptors, GABA-B / chemistry*
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Recombinant Proteins / antagonists & inhibitors
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Stereoisomerism
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Structure-Activity Relationship
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Substrate Specificity
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Xenopus
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gamma-Aminobutyric Acid / analogs & derivatives*
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gamma-Aminobutyric Acid / chemistry
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gamma-Aminobutyric Acid / pharmacology
Substances
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3-amino-2-(S)-hydroxypropyl-methyl-phosphinic acid
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GABA Agonists
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GABA Antagonists
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GABA-C receptor
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Phosphinic Acids
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Receptors, GABA
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Receptors, GABA-B
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Recombinant Proteins
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4-amino-3-hydroxybutyric acid
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gamma-Aminobutyric Acid