Characterization of GABAB ligands in vivo.
1. While GABAB antagonists have been examined in vitro, very few have been tested in vivo. A range of GABAB antagonists were tested against baclofen-induced muscle relaxation and hypothermia. 2. The GABAB antagonists exhibited a range of in vivo activity profiles. 3. CGP 35348 showed clear antagonist effects, while BPBA and 4-ABPA appeared to have agonist properties. 4. Phaclofen, 2-hydroxysaclofen, 3-APPA and 9G seemed to have little effect in this system at the doses tested. 5. Differences between in vivo and in vitro activity could be explained by differences in blood-brain barrier permeability, or possible differences in affinities for the sub-classes of GABAB receptors.
Humeniuk
R E
RE
Department of Clinical and Experimental Pharmacology, University of Adelaide, Australia.
Ong
J
J
Kerr
D I
DI
White
J M
JM
D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004347:Drug Interactions; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology*; D058788:GABA-B Receptor Antagonists; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D009126:Muscle Relaxation / Q000187:drug effects; D009943:Organophosphorus Compounds / Q000494:pharmacology; D015091:beta-Alanine / Q000031:analogs & derivatives / Q000494:pharmacology
C024799:2-phenyl-3-aminopropanoic acid; D018756:GABA Antagonists; D058788:GABA-B Receptor Antagonists; D008024:Ligands; D009943:Organophosphorus Compounds; C052329:phaclofen; D015091:beta-Alanine; C066430:CGP 35348; D001418:Baclofen; C057491:2-hydroxysaclofen