QX-314 blocks the potassium but not the sodium-dependent component of the opiate response in locus coeruleus neurons

Brain Res. 1994 Mar 14;639(2):320-4. doi: 10.1016/0006-8993(94)91746-9.

Abstract

Opiates hyperpolarize locus coeruleus neurons by simultaneously opening K+ channels and turning off a resting Na(+)-dependent inward current. Intracellularly applied QX-314 reduced the opiate current to approximately 40% of the control and the residual current did not reverse near EK, suggesting lack of a significant K+ component. Replacement of Na+ virtually abolished the residual opiate response. Thus, QX-314 blocks the K+ but not the Na(+)-dependent component of the opiate-induced outward current in LC neurons.

MeSH terms

  • Anesthetics, Local / pharmacology*
  • Animals
  • Enkephalin, Methionine / pharmacology
  • Enkephalins / pharmacology
  • In Vitro Techniques
  • Lidocaine / analogs & derivatives*
  • Lidocaine / pharmacology
  • Locus Coeruleus / cytology
  • Locus Coeruleus / drug effects
  • Locus Coeruleus / metabolism*
  • Narcotic Antagonists*
  • Neural Conduction / drug effects
  • Neurons / drug effects
  • Neurons / metabolism*
  • Potassium Channels / drug effects*
  • Rats
  • Receptors, Opioid / drug effects
  • Sodium Channels / drug effects*

Substances

  • Anesthetics, Local
  • Enkephalins
  • Narcotic Antagonists
  • Potassium Channels
  • Receptors, Opioid
  • Sodium Channels
  • QX-314
  • Enkephalin, Methionine
  • Lidocaine