Stimulation by phaclofen of inositol 1,4,5-triphosphate production in cultured neurons from chick tectum.
The influence of gamma-aminobutyric acid (GABA) receptor agonists and antagonists on the intracellular concentration of inositol 1,4,5-triphosphate (IP3) was examined in neuronal cultures of embryonic chick tectum. GABA and selective agonists of its receptors were inactive, whereas phaclofen, a GABA-B receptor antagonist, increased IP3 levels in a concentration-dependent manner. This effect occurred at phaclofen concentrations much lower than those required to affect GABA-B receptors. It is concluded that phaclofen, in addition to its known effect at GABA-B receptors, is also active at an as-yet undefined site.
Michler
A
A
Department of Anatomy, Georg August University, Göttingen, F.R.G.
Erdö
S L
SL
D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives* / Q000494:pharmacology; D002642:Chick Embryo; D007292:Inosine Nucleotides / Q000378:metabolism*; D007293:Inosine Triphosphate / Q000378:metabolism*; D007555:Isoxazoles / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology; D013477:Superior Colliculi / Q000187:drug effects / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D007292:Inosine Nucleotides; D007555:Isoxazoles; D011963:Receptors, GABA-A; C052329:phaclofen; D007293:Inosine Triphosphate; D005680:gamma-Aminobutyric Acid; D001418:Baclofen; C015542:gaboxadol