These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Mitochondrial ATP-sensitive potassium channel activation protects cerebellar granule neurons from apoptosis induced by oxidative stress.
    Author: Teshima Y, Akao M, Li RA, Chong TH, Baumgartner WA, Johnston MV, Marbán E.
    Journal: Stroke; 2003 Jul; 34(7):1796-802. PubMed ID: 12791941.
    Abstract:
    BACKGROUND AND PURPOSE: Mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels are present in the brain, and several reports have shown that mitoK(ATP) channel openers protect the brain against ischemic injury. However, the precise mechanisms of this protection are not well established. We hypothesized that mitoK(ATP) channel openers prevent apoptosis by preserving mitochondrial membrane potential. METHODS: We investigated the effect of mitoK(ATP) channel openers on apoptosis induced by oxidative stress using cultured cerebellar granule neurons. RESULTS: The mitoK(ATP) channel opener diazoxide (100 micromol/L) significantly suppressed the number of cells with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive nuclei and the increase in caspase-3 activity induced by 20 micromol/L H2O2. Diazoxide and another opener, pinacidil, prevented the loss of mitochondrial inner membrane potential (Delta(Psi)m) induced by H2O2. These effects were abolished by 5-hydroxydecanoate (500 micromol/L), a mitoK(ATP) channel blocker. Cyclosporin A and bongkrekic acid, inhibitors of the mitochondrial permeability transition pore, also prevented Delta(Psi)m loss, confirming the involvement of the mitochondrial permeability transition in the apoptotic cascade in neurons. Furthermore, diazoxide prevented the increase in extracellular glutamate concentration induced by H2O2, but this effect was not attributable to activation of surface K(ATP) channels. CONCLUSIONS: MitoK(ATP) channel openers inhibited apoptosis by preserving mitochondrial inner membrane potential. These beneficial effects may suggest a possible new target for neuroprotection.
    [Abstract] [Full Text] [Related] [New Search]