title: 3-amino-2-hydroxy-N-(4-nitrophenyl)-propanesulphonamide, a new class of GABAB receptor antagonist in central and peripheral preparations.
abstract: Racemic 3-amino-2-hydroxy-N-(4-nitrophenyl)-propanesulphonamide (AHPNS), a sulphonamide analog of GABA, reversibly and competitively antagonised the concentration-dependent depression of cholinergic twitch contractions by baclofen, in the electrically stimulated guinea-pig isolated ileum, with a pA2 of 4.0 +/- 0.2. In the rat neocortex, maintained in Mg(2+)-free medium, AHPNS (100-500 microM) also reversibly antagonised the baclofen (10 microM)-induced suppression of spontaneous discharges. AHPNS is a new class of GABAB receptor antagonist that has central and peripheral blocking actions.
authors.affiliation: Department of Anaesthesia and Intensive Care, University of Adelaide, South Australia, Australia.
authors.forename: D I
authors.initials: DI
authors.lastname: Kerr
authors.forename: J
authors.initials: J
authors.lastname: Ong
authors.forename: R
authors.initials: R
authors.lastname: Hughes
authors.forename: R H
authors.initials: RH
authors.lastname: Prager
mesh_terms: D000818:Animals; D001418:Baclofen / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002490:Central Nervous System / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004558:Electric Stimulation; D018755:GABA Agonists / Q000494:pharmacology; D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008274:Magnesium / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010275:Parasympathetic Nervous System / Q000187:drug effects; D017933:Peripheral Nervous System / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: C103726:3-amino-2-hydroxy-N-(4-nitrophenyl)propanesulfonamide; D018755:GABA Agonists; D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D013449:Sulfonamides; D001418:Baclofen; D008274:Magnesium