Interaction of pentobarbitone and gamma-aminobutyric acid on mammalian sympathetic ganglion cells.
1. Interactions of bath-applied pentobarbitone and gamma-aminobutyric acid (GABA) on neurones in isolated superior cervical ganglia of the rat have been examined with intracellular microelectrodes. 2. Pentobarbitone itself (30 micrometer-1 mM) showed no clear or consistent GABA-like effects: changes in resting input conductance and membrane potential were small and variable. 3. Pentobarbitone (100 micrometer) strikingly enhanced the conductance increases produced by GABA and 3-aminopropanesulphonic acid, and reversed the depression of GABA-evoked responses by bicuculline. 4. It is concluded that reversal of bicuculline action at the membrane conductance level might be explained by augmentation of GABA-action. This augmentation cannot be attributed to 'partial agonist' properties of pentobarbitone or to interference with glial transport processes.
D000613:Aminobutyrates / Q000037:antagonists & inhibitors*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D004357:Drug Synergism; D018756:GABA Antagonists; D008564:Membrane Potentials / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects*; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D013654:Taurine / Q000031:analogs & derivatives / Q000494:pharmacology
D000613:Aminobutyrates; D018756:GABA Antagonists; D013654:Taurine; D010424:Pentobarbital; D001640:Bicuculline