title: Evidence that antagonism by delta-aminovaleric acid of GABAB receptors in the guinea-pig ileum may be due to an interaction between GABAA and GABAB receptors.
abstract: The antagonism by delta-aminovaleric acid has been investigated using electrically stimulated segments of isolated guinea-pig ileum. The depression of the twitch response by baclofen was antagonized by delta-aminovaleric acid and this antagonism is also mimicked by the selective GABAA agonists, 3-aminopropanesulphonic acid and isoguvacine. The GABAA antagonist bicuculline reversed the antagonism of the baclofen response. These results indicate that this antagonism of GABAB receptors may be due to GABAA receptor modulation of GABAB receptors.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D021542:Amino Acids, Neutral; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007539:Isonicotinic Acids / Q000494:pharmacology; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D011963:Receptors, GABA-A / Q000187:drug effects*; D013654:Taurine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D021542:Amino Acids, Neutral; D007539:Isonicotinic Acids; D011963:Receptors, GABA-A; D013654:Taurine; C001355:tramiprosate; C013809:5-aminovaleric acid; D001418:Baclofen; D001640:Bicuculline; C015300:isoguvacine