Ca(2+)-dependent K+ channel activity in rat glioma cells induced by bradykinin stimulation and by inositol 1,4,5-trisphosphate injection.
1. A glial cell line derived from C6 rat glioma cells has been shown previously to respond to extracellular pulses of bradykinin or intracellular injection of inositol 1,4,5-trisphosphate (Ins-P3) with a slow hyperpolarizing response due to activation of a K+ current (G. Reiser et al., Brain Res. 506, 205-214; 1990). 2. We determined the ensuing single-channel activity, which is most likely caused by Ca2+ released from internal stores after bradykinin stimulation. Bradykinin-activated channels were selectively permeable to K+, but not to Na+ or to Cl-, and exhibited conductances of mainly 40 and 50 pS. In glioma cells the same type of channel was activated by intracellular injection of Ins-P3 and by extracellular bradykinin pulses.
Binmöller
F J
FJ
Physiologisch-chemisches Institut, Universität Tübingen, Germany.
Reiser
G
G
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D005910:Glioma; D015544:Inositol 1,4,5-Trisphosphate / Q000008:administration & dosage / Q000494:pharmacology*; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D014407:Tumor Cells, Cultured
D015221:Potassium Channels; D015544:Inositol 1,4,5-Trisphosphate; D001920:Bradykinin; D002118:Calcium