title: Low Ca2+-sensitive maxi-K+ channels in human cultured fibroblasts.
abstract: The patch clamp technique was used to reveal single channel activity in the membrane of human cultured fibroblasts. The most frequently detected ion channel type was a Ca2+-dependent K+ channel with a conductance of 287 +/- 38 pS in symmetrical 130 mM KCl. The channel showed a peculiar low Ca2+-sensitivity compared to that of similar channels in other preparations. In fact micromolar values of internal Ca2+ were not effective in the channel activation, except at high depolarizing membrane potentials. The activity was highly increased only when the channel was exposed to relatively high internal Ca2+ concentrations (0.2-2.0 mM).
authors.affiliation: Laboratorio di Genetica Molecolare, Istituto G. Gaslini, Genova, Italy.
authors.forename: L J
authors.initials: LJ
authors.lastname: Galietta
authors.forename: Z
authors.initials: Z
authors.lastname: Galdzicki
authors.forename: M
authors.initials: M
authors.lastname: Nobile
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002478:Cells, Cultured; D004594:Electrophysiology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D006801:Humans; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D012867:Skin / Q000166:cytology* / Q000187:drug effects; D012879:Skin Physiological Phenomena
chemical_list: D015221:Potassium Channels; D002118:Calcium