Characterization of stretch-activated ion channels in cultured astrocytes

Glia. 1993 Jun;8(2):87-96. doi: 10.1002/glia.440080204.

Abstract

The presence of a stretch-activated channel in rat cerebellar astrocytes in culture is described. This stretch-sensitive channel is K(+)-selective and its open probability increases with suction following a Boltzmann-like distribution with half activation at 45 mm Hg. Kinetic analysis of the single-channel data indicated that there are two open and two closed states and that the shortest time constants of both open and closed states are the most sensitive to suction. A symmetrical two-barrier-one-site permeation model can quantitatively describe the inward rectification of the single-channel current to voltage relations. It is suggested that this stretch-activated channel plays a role in the regulatory volume response of astrocytes to hyposmotic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / drug effects
  • Astrocytes / metabolism*
  • Bucladesine / pharmacology
  • Cations / metabolism
  • Cell Size
  • Cells, Cultured
  • Hypotonic Solutions / pharmacology
  • Ion Channel Gating
  • Kinetics
  • Mechanoreceptors / metabolism*
  • Membrane Potentials
  • Potassium / metabolism*
  • Potassium Channels / metabolism*
  • Pressure
  • Rats

Substances

  • Cations
  • Hypotonic Solutions
  • Potassium Channels
  • Bucladesine
  • Potassium