Intracellular ATP changes the voltage-dependence of delayed rectifier potassium current in bullfrog primary afferent neurons.
Dissociated bullfrog dorsal root ganglion cells were voltage-clamped in the whole-cell configuration to study the steady-state activation and inactivation curves for a delayed rectifier potassium current. The 50%-activation of the current occurred at +15 mV when measured with ATP (5 mM) in the pipette solution as opposed to -11 mV with 5'-adenylylimidodiphosphate (AMP-PNP, 5 mM) and -15 mV with adenosine 5'-O-(3-thiotriphosphate) (5 mM). The 50%-inactivation of the current occurred at -6 mV with ATP but at -31 mM with AMP-PNP. The results suggest that intracellular ATP modulates voltage-dependence of the delayed rectifier in amphibian afferent neurons.
Tokimasa
T
T
Department of Physiology, Kurume University School of Medicine, Japan.
Tsurusaki
M
M
Ishimatsu
M
M
Akasu
T
T
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D005727:Ganglia, Spinal / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011892:Rana catesbeiana; D013873:Thionucleotides / Q000494:pharmacology
D015221:Potassium Channels; D013873:Thionucleotides; D000266:Adenylyl Imidodiphosphate; C022570:adenosine 5'-O-(2-thiotriphosphate); D000255:Adenosine Triphosphate