Voltage gating of Ca2(+)-activated potassium channels in human lymphocytes.
The effect of membrane potential on Ca2+ activated K+ channels was studied on human peripheral lymphocytes. Membrane potential was monitored using bisoxonol and flow cytometry. 1 mM Ca2+ in the presence of 2 microM ionomycin depolarized the control cell population, while 100 microM Ca2+ caused hyperpolarization. However 1 mM Ca2+ had a hyperpolarizing effect on previously partially depolarized cells. Potassium channel blockers did not influence the depolarization, while they inhibited the hyperpolarization. Based on the experimental evidence a voltage gating of Ca2+ activated K+ channels is suggested.
Mátyus
L
L
Department of Biophysics, University Medical School of Debrecen, Hungary.
Pieri
C
C
Recchioni
R
R
Moroni
F
F
Bene
L
L
Trón
L
L
Damjanovich
S
S
D002118:Calcium / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D015759:Ionomycin / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000502:physiology; D008214:Lymphocytes / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D015221:Potassium Channels / Q000502:physiology*
D015221:Potassium Channels; D015759:Ionomycin; D002118:Calcium