Regulatory mechanisms involved in the activation of bradykinin-induced membrane currents in PC12 cells.
Whole-cell patch-clamp measurements were made in nerve-growth-factor (NGF)-treated PC12 cells. External application of bradykinin (BK) activated an outward and an inward current which could be separated by using KCl- or CsCl-containing pipette solutions. The slowly activating inward current could be induced by BK independently of the filling of intracellular Ca2+ stores. By using GDP-beta-S in the pipette medium, we showed that BK-induced outward and inward currents were differentially regulated through G-protein-sensitive and -insensitive mechanisms, respectively. While the outward current was inhibited by GDP-beta-S, the inward current was not affected. Our results show that occupancy of BK receptors activates different signaling pathways for the induction of outward and inward currents.
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D007473:Ion Channels / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D016716:PC12 Cells; D018408:Patch-Clamp Techniques; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin
D004791:Enzyme Inhibitors; D007473:Ion Channels; D013729:Terpenes; D019284:Thapsigargin; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D000252:Calcium-Transporting ATPases; D001920:Bradykinin