A primary role for K+ and Na+ efflux in the activation of apoptosis.

Journal Article (Journal Article)

Cell shrinkage is a major characteristic of apoptosis, but the mechanism and role of this process in cell death are poorly understood. The primary factor that controls volume regulation in all cells is ions, and thus we have examined the movement of ions at the single cell level in lymphocytes during apoptosis. Activation of the death program with several stimuli that act through independent pathways to stimulate apoptosis results in a synchronous shift of cells from a normal cell size to a shrunken cell size. Only the shrunken cells exhibit DNA fragmentation and an approximate 4-fold elevation of caspase-3-like activity. Analysis of K+ and Na+ ion content of individual cells by flow cytometry revealed that the intracellular ionic strength of apoptotic cells decreased substantially from their non-shrunken counterparts. Additionally, we show apoptosis is enhanced under conditions where the intracellular K+ concentration is diminished and that apoptosis is inhibited when K+ efflux is prevented. These data show that the efflux of ions, primarily potassium, plays a necessary and perhaps a pivotal role in the cell death program.

Full Text

Duke Authors

Cited Authors

  • Bortner, CD; Hughes, FM; Cidlowski, JA

Published Date

  • December 19, 1997

Published In

Volume / Issue

  • 272 / 51

Start / End Page

  • 32436 - 32442

PubMed ID

  • 9405453

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.272.51.32436


  • eng

Conference Location

  • United States