Abstract
Stimulation of beta-adrenergic receptors (betaARs) causes apoptosis in adult rat ventricular myocytes (ARVMs). The role of reactive oxygen species (ROS) in mediating betaAR-stimulated apoptosis is not known. Stimulation of betaARs with norepinephrine (10 micromol/L) in the presence of prazosin (100 nmol/L) for 24 hours increased the number of apoptotic myocytes as determined by TUNEL staining by 3.6- fold. The superoxide dismutase/catalase mimetics Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP; 10 micromol/L) and Euk-134 decreased betaAR-stimulated apoptosis by 89+/-6% and 76+/-10%, respectively. Infection with an adenovirus expressing catalase decreased betaAR-stimulated apoptosis by 82+/-15%. The mitochondrial permeability transition pore inhibitor bongkrekic acid (50 micromol/L) decreased betaAR-stimulated apoptosis by 76+/-8%, and the caspase inhibitor zVAD-fmk (25 micromol/L) decreased betaAR-stimulated apoptosis by 62+/-11%. betaAR-stimulated cytochrome c release was inhibited by MnTMPyP. betaAR stimulation caused c-Jun NH2-terminal kinase (JNK) activation, which was abolished by MnTMPyP. Transfection with an adenovirus expressing dominant-negative JNK inhibited betaAR-stimulated apoptosis by 81+/-12%, and the JNK inhibitor SP600125 inhibited both betaAR-stimulated apoptosis and cytochrome c release. Thus, betaAR-stimulated apoptosis in ARVMs involves ROS/JNK-dependent activation of the mitochondrial death pathway.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Apoptosis / drug effects
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Apoptosis / physiology*
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Bongkrekic Acid / pharmacology
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Caspase Inhibitors
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Catalase / biosynthesis
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Catalase / genetics
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Catalase / pharmacology
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Cells, Cultured
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Cytochrome c Group / metabolism
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Enzyme Inhibitors / pharmacology
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Free Radical Scavengers / pharmacology
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Ion Channels / antagonists & inhibitors
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JNK Mitogen-Activated Protein Kinases
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Metalloporphyrins / pharmacology
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Mitochondria / drug effects
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Mitochondria / metabolism
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Permeability Transition Pore
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Mitogen-Activated Protein Kinases / antagonists & inhibitors
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Mitogen-Activated Protein Kinases / genetics
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Mitogen-Activated Protein Kinases / metabolism*
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Myocytes, Cardiac / cytology
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Myocytes, Cardiac / metabolism*
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Norepinephrine / pharmacology
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Organometallic Compounds / pharmacology
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Prazosin / pharmacology
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Rats
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Reactive Oxygen Species / metabolism*
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Receptors, Adrenergic, beta / drug effects
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Receptors, Adrenergic, beta / metabolism*
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Salicylates / pharmacology
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Signal Transduction / physiology
Substances
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Caspase Inhibitors
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Cytochrome c Group
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EUK-134
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Enzyme Inhibitors
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Free Radical Scavengers
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Ion Channels
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Metalloporphyrins
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Permeability Transition Pore
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Organometallic Compounds
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Reactive Oxygen Species
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Receptors, Adrenergic, beta
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Salicylates
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Bongkrekic Acid
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tetrakis(N-methyl-4-pyridiniumyl)porphine manganese(III) complex
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Catalase
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JNK Mitogen-Activated Protein Kinases
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Mitogen-Activated Protein Kinases
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Norepinephrine
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Prazosin