Abstract
To determine whether blockade of non-N-methyl-D-aspartate (non-NMDA) excitatory amino acid receptors affects breathing, we administered the non-NMDA receptor antagonist, 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX), to anesthetized cats while monitoring phrenic nerve discharge, blood pressure and heart rate. NBQX, 3 and 10 mg/kg, i.v., reduced phrenic amplitude 59 +/- 20% (n = 3) and 88 +/- 6% (n = 5), respectively, and decreased respiratory rate. Phrenic activity was completely silenced in 3 animals. These effects were accompanied by decreased blood pressure and heart rate. Our data indicate that NBQX, a competitive antagonist of non-NMDA receptors, is a powerful depressant of cardiorespiratory activity.
MeSH terms
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Animals
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Apnea / chemically induced
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Apnea / physiopathology
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Atrial Function / drug effects
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Atrial Function / physiology
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Blood Pressure / drug effects
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Blood Pressure / physiology
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Cats
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Dose-Response Relationship, Drug
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Excitatory Amino Acid Antagonists / administration & dosage
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Excitatory Amino Acid Antagonists / adverse effects*
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Heart Rate / drug effects
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Injections, Intravenous
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Phrenic Nerve / drug effects
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Phrenic Nerve / physiology
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Quinoxalines / administration & dosage
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Quinoxalines / adverse effects*
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Respiratory Insufficiency / chemically induced*
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Respiratory Physiological Phenomena / drug effects
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Respiratory System / drug effects
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Respiratory System / innervation
Substances
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Excitatory Amino Acid Antagonists
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Quinoxalines
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2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline