title: Activation of basolateral membrane K+ permeability by bradykinin in MDCK cells.
abstract: We study bradykinin-stimulated K+ efflux in Madin-Darby canine kidney (MDCK) cells using 86Rb as an isotopic tracer. Bradykinin brings about a rapid increase in the permeability of MDCK cells to K+, the effect is dose-dependent with a plateau at 10(-6) M. The effect seems to be mediated by Ca2+-activated K+ channels, localised at the basolateral aspect of the epithelium. Unlike alpha-receptors, which mediate a similar effect of adrenalin in these cells, bradykinin receptors seem to be present at both sides of the epithelium. Bradykinin increases the labelling of IP3, and bradykinin-stimulated K+ efflux persists even in cells which are bathed in Ca2+-free medium, suggesting that the effects seen in the present work are probably due to Ca2+ release from intracellular stores. Some extracellular Ca2+ also might be involved in the bradykinin effect, consistent with the kinin-increasing membrane permeability to Ca2+.
mesh_terms: D000818:Animals; D001464:Barium / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D011803:Quinine / Q000494:pharmacology; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D012414:Rubidium Radioisotopes
chemical_list: D007295:Inositol Phosphates; D007473:Ion Channels; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter; D012414:Rubidium Radioisotopes; D001464:Barium; D000001:Calcimycin; D015544:Inositol 1,4,5-Trisphosphate; D011803:Quinine; D011188:Potassium; D001920:Bradykinin; D002118:Calcium