Protein kinase C as mediator of arachidonic acid-induced decrease of neuronal M current.
The M current, IM, of NG108-15 neuroblastoma x glioma hybrid cells, a non-inactivating K+ current, is decreased by arachidonic acid (5-25 microM), often after an initial transitory increase. To test the possibility that the decrease is caused by activation of protein kinase C (PKC) we used the PKC 19-31 peptide, which is an effective inhibitor of PKC. With 1 microM peptide in the pipette solution the normally observed strong reduction of IM by 1 microM phorbol 12,13-dibutyrate (PDB) was almost totally prevented, indicating that PKC is completely inhibited; also the voltage dependence of the M conductance, gM(V), was shifted to more negative membrane potentials. In the presence of 1 microM peptide the effect of 25 microM arachidonic acid on IM was significantly reduced, suggesting that the effect, or at least a large part of it, is mediated by PKC.
Schmitt
H
H
I. Physiologisches Institut, Universität des Saarlandes, Homburg-Saar, Germany.
Meves
H
H
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D004553:Electric Conductivity; D005910:Glioma; D006822:Hybrid Cells; D008564:Membrane Potentials; D051379:Mice; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D014407:Tumor Cells, Cultured
D010446:Peptide Fragments; D016718:Arachidonic Acid; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C