Voltage gating of Ca2(+)-activated potassium channels in human lymphocytes

Biochem Biophys Res Commun. 1990 Aug 31;171(1):325-9. doi: 10.1016/0006-291x(90)91396-a.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / physiology*
  • Humans
  • In Vitro Techniques
  • Ion Channel Gating*
  • Ionomycin / pharmacology
  • Leukocytes, Mononuclear / physiology
  • Lymphocytes / physiology*
  • Membrane Potentials / drug effects
  • Potassium Channels / physiology*

Substances

  • Potassium Channels
  • Ionomycin
  • Calcium