Interactions of gamma-aminobutyric acid (GABA), pentobarbital, and homopantothenic acid (HOPA) on internally perfused frog sensory neurons.
Augmentatory actions among Cl- currents (ICl) induced by gamma-aminobutyric acid (GABA), pentobarbital (PB), and homopantothenic acid (HOPA) were investigated in isolated frog sensory neurons after suppression of Na+, K+, and Ca2+ currents using a suction pipette technique which combines internal perfusion with voltage clamp. GABA-sensitive neurons responded to both PB and HOPA, and the responses behaved as a simple Cl- electrode and reversed at the Cl- equilibrium potential (ECl). The dose-response curve for GABA-induced Cl- conductance was sigmoidal with the GABA concentration producing a half-maximum response (4.2 X 10(-5) M). Both GABA and HOPA dose-response curves shifted to the left in the presence of PB, though the facilitatory action of PB on GABA- and HOPA-induced ICl was more effective in the former. There was a significant facilitatory interaction between GABA- and HOPA-induced ICl. It is concluded that HOPA affects the GABA-GABA or PB-PB receptor interactions.
N
N
Akaike
Y
Y
Oomura
D000818:Animals; D002469:Cell Separation; D002712:Chlorides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005727:Ganglia, Spinal / Q000166:cytology; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects*; D010205:Pantothenic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D010424:Pentobarbital / Q000494:pharmacology*; D010477:Perfusion; D011898:Ranidae; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*
D002712:Chlorides; D007473:Ion Channels; C016030:pantogab; D010205:Pantothenic Acid; D005680:gamma-Aminobutyric Acid; D010424:Pentobarbital