Activation of large conductance Ca(2+)-activated K+ channels in N1E-115 neuroblastoma cells by platelet-activating factor.
Using patch-clamp single channel recording techniques, we reported a Platelet-Activating Factor "PAF"-induced activation of large conductance Ca(2+)-activated K+ "BK(Ca)" channels in N1E-115 cells. This activation was only observed in cell-attached configuration and was blocked by the PAF antagonist BN50739 or removal of calcium from the bath. Nanomolar concentration of PAF produced a transient hyperpolarization observed in whole-cell current clamp configuration which was blocked by the bath application of BN50739 or iberiotoxin. Our results suggest that the PAF-induced hyperpolarization is mediated by an activation of BK(Ca) channels coupled to specific PAF receptors. This coupling is not direct and results from the PAF-induced elevation in cytosolic free Ca2+ concentrations that we have previously described in N1E-115 cells (Cell Calcium 1995, 17, 442-452).
Diserbo
M
M
Centre de Recherches Emile Pardé, La Tronche, France.
Fatôme
M
M
Verdetti
J
J
D001381:Azepines / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D015640:Ion Channel Gating; D008564:Membrane Potentials; D009447:Neuroblastoma; D009474:Neurons / Q000502:physiology*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D015221:Potassium Channels / Q000502:physiology*; D014230:Triazoles / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D001381:Azepines; D010972:Platelet Activating Factor; D015221:Potassium Channels; D014230:Triazoles; C064509:BN 50739; D002118:Calcium