Proceedings of the Royal Society of London. Series B, Biological sciences · 1987 · 56 citations · 24 references
Life SciencesBiochemistryPharmacologyCell SignalingMolecular PharmacologySignal TransductionCholinergic SignalingIon Channel PhysiologyIon Channel RegulationIon ChannelsMembrane ElectrophysiologyPhosphoinositide SignalingCell-attached Patch ClampCholinergic Signal TransductionOpen TimePatch Clamp TechniquesPatch-clamp RecordingPhosphoinositide KinasesPhosphoinositide Regulation Of Ion ChannelsPhospholipase C Signaling
Acetylcholine (ACh)-activated channel properties were examined on an aneural culture of chick embryo myotubes by using patch-clamp techniques. Changes in conductance, open time and closed time were induced by the selective activator of the calcium- and phospholipid-dependent C-kinase (PKc), 12-O-tetradecanoylphorbol-13-acetate (TPA). The action of TPA was mimicked by exogenous phospholipase C and was blocked by the PKc inhibitor, 1-(5-isoquinolinylsulphonyl)-2-methyl-piperazine. In addition to its gating action, ACh was shown to stimulate phosphoinositide turnover and to translocate PKc from the cytosol to the cell membrane. Both these ACh-induced effects were inhibited by curare and not substantially affected by atropine. Bath-applied ACh outside the patch-pipette in the cell-attached patch-clamp mode, had a strong effect on the ACh-activated channels in the patch membrane, in a way that resembled the action of TPA. These findings raise the possibility that ACh regulates its own nicotinic receptors through the C-kinase system.
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