Abstract
An in vitro ischemia model was used to determine the molecular mechanisms responsible for the ischemia-induced neuronal cell death. Additionally, the neuronal protective mechanisms of anti-apoptotic drugs against ischemia were also evaluated. In this study, the primary neuronal cultures were incubated in an anoxic chamber with 95% of N2 and 5% of CO2 for various times. The death rate, degree of the apoptotic damage, reduction of mitochondrial membrane potential, translocation of Bax, release of cytochrome C and activation of caspase-9 and -3 were determined at each time point. Results showed that a Bax-regulated mitochondria- mediated apoptosis is responsible for the in vitro ischemia-induced neuronal death. Reduction in mitochondrial membrane potential plays no role in triggering this apoptosis. Furthermore, the anti-apoptotic drugs: furosemide (a Bax blocker) and ZVAD-fmk (caspase inhibitor) but not cyclosporine A (a MPT pore blocker), significantly protected the neurons against ischemia-induced damage. This provides an additional consideration in the future selection of new anti-ischemic drugs.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Apoptosis / drug effects
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Apoptosis / physiology*
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Brain Ischemia / metabolism*
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Brain Ischemia / physiopathology
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Caspases / drug effects
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Caspases / metabolism
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Cerebral Infarction / metabolism
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Cerebral Infarction / physiopathology
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Cytochromes c / drug effects
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Cytochromes c / metabolism
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Disease Models, Animal
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Enzyme Inhibitors / pharmacology
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Intracellular Membranes / drug effects
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Intracellular Membranes / metabolism
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Mitochondria / drug effects
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Mitochondria / metabolism*
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Nerve Degeneration / metabolism*
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Nerve Degeneration / physiopathology
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Protein Synthesis Inhibitors / pharmacology
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Protein Transport / drug effects
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Protein Transport / physiology
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Proto-Oncogene Proteins c-bcl-2 / metabolism*
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Rats
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Rats, Sprague-Dawley
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Signal Transduction / drug effects
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Signal Transduction / physiology
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bcl-2-Associated X Protein
Substances
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Bax protein, rat
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Enzyme Inhibitors
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Protein Synthesis Inhibitors
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Proto-Oncogene Proteins c-bcl-2
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bcl-2-Associated X Protein
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Cytochromes c
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Caspases