Effects of PKC on inhibition of delayed rectifier potassium currents by N/OFQ.
Nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the opioid receptor-like-1 (ORL-1) orphan receptor, which is responsible for inhibition of delayed rectifier potassium current (I(K)). But its mechanism of N/OFQ acting on I(K) is not clear and whether PKC is involved in the modulation of this processing is still unknown. Whole-cell patch-clamp recordings were performed in acutely dissociated rat parietal cortical neurons. Bath application of N/OFQ (10 nM-10 microM) resulted in a dose-dependent depression of I(K) with partially recovery on washout. Furthermore, we investigated the role of PKC in the inhibition of I(K) by N/OFQ. Chelerythrine, an inhibitor of PKC, attenuated the inhibition of N/OFQ on I(K). On the contrary, PDBu, an activator of PKC, augmented N/OFQ-evoked responses. The present study suggested that N/OFQ inhibited I(K) and PKC was involved in N/OFQ-evoked response in acutely dissociated rat cerebral parietal cortical neurons.
Qu
Lihui
L
Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081, China.
Li
Yurong
Y
Tian
Hua
H
Wang
Zhigang
Z
Cui
Lanwei
L
Jin
Hongbo
H
Wang
Wei
W
Yang
Lei
L
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology; D002540:Cerebral Cortex / Q000502:physiology; D004789:Enzyme Activation; D005260:Female; D008297:Male; D009474:Neurons / Q000502:physiology; D018847:Opioid Peptides / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010446:Peptide Fragments / Q000502:physiology*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D024661:Potassium Channels, Inwardly Rectifying / Q000037:antagonists & inhibitors*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats
D000470:Alkaloids; D053119:Benzophenanthridines; D018847:Opioid Peptides; D010446:Peptide Fragments; D024661:Potassium Channels, Inwardly Rectifying; C466980:nociceptin orphanin FQ(1-17)OH; D015240:Phorbol 12,13-Dibutyrate; C016299:chelerythrine; D011493:Protein Kinase C