Neuropeptide FF and FMRFamide potentiate acid-evoked currents from sensory neurons and proton-gated DEG/ENaC channels.
Acidosis is associated with inflammation and ischemia and activates cation channels in sensory neurons. Inflammation also induces expression of FMRFamidelike neuropeptides, which modulate pain. We found that neuropeptide FF (Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe amide) and FMRFamide (Phe-Met-Arg-Phe amide) generated no current on their own but potentiated H+-gated currents from cultured sensory neurons and heterologously expressed ASIC and DRASIC channels. The neuropeptides slowed inactivation and induced sustained currents during acidification. The effects were specific; different channels showed distinct responses to the various peptides. These results suggest that acid-sensing ion channels may integrate multiple extracellular signals to modify sensory perception.
Askwith
C C
CC
Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242, USA.
Cheng
C
C
Ikuma
M
M
Benson
C
C
Price
M P
MP
Welsh
M J
MJ
D062565:Acid Sensing Ion Channels; D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002478:Cells, Cultured; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels; D019835:FMRFamide / Q000494:pharmacology* / Q000502:physiology; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007473:Ion Channels / Q000187:drug effects* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology* / Q000502:physiology; D051381:Rats; D014981:Xenopus
C568424:ASIC2 protein, human; D062565:Acid Sensing Ion Channels; C568425:Asic2 protein, rat; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels; D007473:Ion Channels; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D019835:FMRFamide; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide