M-current suppression in PC12 cells by bradykinin is mediated by a pertussis toxin-insensitive G-protein and modulated by intracellular calcium.
Inhibition of the M-current in PC12 cells by bradykinin has been studied under whole-cell recording conditions. In cells dialyzed with GTP-gamma-S, bradykinin produced a total and irreversible M-current suppression, while the inhibition was attenuated in cells dialyzed with GDP-beta-S. Inhibition occurred in cells pretreated with pertussis toxin, while this treatment prevented the modulation of Ca2+ currents by muscarine. The rate and extent of inhibition increased with the level of intracellular Ca2+ from 0 to 70 nM. These results indicate that a pertussis toxin insensitive G-protein mediates the action of bradykinin on the M-current, and some steps in the second messenger cascade are modulated by Ca2+.
Villarroel
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A
Howard Hughes Medical Institute, SUNY at Stony Brook, USA. alvaro@pinarl.csic.es
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects*; D009116:Muscarine / Q000494:pharmacology; D016716:PC12 Cells / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D037342:Pertussis Toxin; D051381:Rats; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D009116:Muscarine; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D001920:Bradykinin; D002118:Calcium