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: Effect of amyloid beta-peptide on permeability transition pore: a comparative study.
    Author: Moreira PI, Santos MS, Moreno A, Rego AC, Oliveira C.
    Journal: J Neurosci Res; 2002 Jul 15; 69(2):257-67. PubMed ID: 12111807.
    Abstract:
    A potentially central factor in neurodegeneration is the permeability transition pore (PTP). Because of the tissue-specific differences in pore properties, we directly compared isolated brain and liver mitochondria responses to the neurotoxic A beta peptides. For this purpose, the following parameters were examined: mitochondrial membrane potential (Delta Psi m), respiration, swelling, ultrastructural morphology, and content of cytochrome c. Both peptides, A beta(25-35) (50 microM) and A beta(1-40) (2 microM), had a similar toxicity, exacerbating the effects of Ca(2+), although, per se, they did not induce (PTP). In liver mitochondria, A beta led to a drop in Delta Psi m and potentiated matrix swelling and disruption induced by Ca(2+). In contrast, brain mitochondria, exposed to the same conditions, demonstrated a higher capacity to accumulate Ca(2+) before the Delta Psi m drop and a slight increase of mitochondrial swelling compared with liver mitochondria. Furthermore, mitochondrial respiratory state 3 was depressed in the presence of A beta, whereas state 4 was unaltered, resulting in an uncoupling of respiration. In both types of mitochondria, A beta did not affect the content of cytochrome c. The Delta Psi m drop was reversed when Ca(2+) was removed by EGTA or when ADP plus oligomycin was present. Pretreatment with cyclosporin A or ADP plus oligomycin prevented the deleterious effects promoted by A beta and/or Ca(2+). It can be concluded that brain and liver mitochondria show a different susceptibility to the deleterious effect of A beta peptide, brain mitochondria being more resistant to the potentiation by A beta of Ca(2+)-induced PTP.
    [Abstract] [Full Text] [Related] [New Search]