8-Bromo-cAMP blocks opioid activation of a voltage-gated potassium current in isolated hippocampal neurons.
We have previously shown that mu-selective opioid agonists activate both an inward rectifying and a voltage-gated potassium conductance in acutely dissociated non-pyramidal neurons from rat hippocampus. We now report that the opioid-activated voltage-gated potassium conductance was blocked by the membrane permeable cAMP analogue 8-bromo-cAMP. In contrast, 8-bromo-cGMP failed to inhibit opioid activation of the voltage-gated potassium current. These results suggest that the opioid-activated potassium channel is regulated by cAMP-dependent phosphorylation.
Wimpey
T L
TL
Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
Chavkin
C
C
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003864:Depression, Chemical; D004723:Endorphins / Q000494:pharmacology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects; D015640:Ion Channel Gating / Q000187:drug effects*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D010766:Phosphorylation; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects* / Q000502:physiology; D017450:Receptors, Opioid, mu
D004723:Endorphins; D004745:Enkephalins; D015221:Potassium Channels; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D015124:8-Bromo Cyclic Adenosine Monophosphate; C016276:8-bromocyclic GMP; C044708:morphiceptin, N-Me-Phe(3)-; D006152:Cyclic GMP; D011188:Potassium