QX-314 blocks the potassium but not the sodium-dependent component of the opiate response in locus coeruleus neurons.
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.
Alreja
M
M
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06508.
Aghajanian
G K
GK
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D004744:Enkephalin, Methionine / Q000494:pharmacology; D004745:Enkephalins / Q000494:pharmacology; D066298:In Vitro Techniques; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008125:Locus Coeruleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009292:Narcotic Antagonists; D009431:Neural Conduction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects; D015222:Sodium Channels / Q000187:drug effects*
D000779:Anesthetics, Local; D004745:Enkephalins; D009292:Narcotic Antagonists; D015221:Potassium Channels; D011957:Receptors, Opioid; D015222:Sodium Channels; C012647:QX-314; D004744:Enkephalin, Methionine; D008012:Lidocaine