ATP-sensitive potassium channels in rat primary afferent neurons: the effect of neuropathic injury and gabapentin.
ATP-sensitive potassium (K(ATP)) currents were examined in dorsal root ganglion neurons from neuropathic and control rats using whole-cell voltage clamp recordings. K(ATP) channel openers (diazoxide and pinacidil) enhanced, and the blocker glibenclamide inhibited an outward current in control neurons in a manner dependent on the pipette ATP concentration. Analysis of reversal potentials showed that this current is carried by K(+) ions. Outward current in cells from rats with peripheral nerve injury was not sensitive to modulators of K(ATP) channels. Gabapentin, a putative K(ATP) channel opener, had minimal effect on currents in either group of neurons. We conclude that normal primary afferent neurons express K(ATP) channels that conduct current which is eliminated by peripheral nerve injury. Gabapentin does not affect this current significantly.
Sarantopoulos
Constantine
C
Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. csar@mcw.edu
McCallum
Bruce
B
Sapunar
Damir
D
Kwok
Wai-Meng
WM
Hogan
Quinn
Q
D018528:ATP-Binding Cassette Transporters; D000085:Acetates / Q000494:pharmacology*; D000588:Amines; D000818:Animals; D001479:Basal Ganglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D003509:Cyclohexanecarboxylic Acids; D003981:Diazoxide / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D000077206:Gabapentin; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects; D005905:Glyburide / Q000494:pharmacology; D054086:KATP Channels; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000473:pathology*; D020110:Pinacidil / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000819:agonists* / Q000187:drug effects / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying; D051381:Rats; D017207:Rats, Sprague-Dawley; D005680:gamma-Aminobutyric Acid
D018528:ATP-Binding Cassette Transporters; D000085:Acetates; D000588:Amines; D003509:Cyclohexanecarboxylic Acids; D018691:Excitatory Amino Acid Antagonists; D054086:KATP Channels; D018696:Neuroprotective Agents; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; C092520:uK-ATP-1 potassium channel; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D020110:Pinacidil; D003981:Diazoxide; D005905:Glyburide