Abstract
The effects of prolonged (21 day) oral administration of the antidepressants paroxetine (0.9 to 8.9 mg/kg/day) and amitriptyline (2.7 to 27 mg/kg/day), on rat brain cortical beta 1- and beta 2-adrenoceptor numbers and affinities were investigated using [3H]-CGP 12177. Although amitriptyline, 27 mg/kg, caused a significant (p less than 0.05) 20% reduction in the number of beta 1-adrenoceptors, paroxetine, at doses up to 8.9 mg/kg p.o., did not influence binding of [3H]-CGP 12177 to cortical beta 1- or beta 2-adrenoceptors. This study with paroxetine provides further evidence that the down-regulation of central beta 1-adrenoceptors in rat brain after repeated administration is not a property of all antidepressant drugs.
MeSH terms
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Adrenergic beta-Antagonists
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Amitriptyline / pharmacology
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Animals
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Antidepressive Agents / pharmacology*
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Cerebral Cortex / drug effects
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Cerebral Cortex / metabolism*
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Dose-Response Relationship, Drug
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Imidazoles
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Kinetics
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Male
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Neurotransmitter Uptake Inhibitors / pharmacology*
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Paroxetine
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Piperidines / pharmacology*
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Propanolamines
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Radioligand Assay
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Rats
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Receptors, Adrenergic, beta / classification
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Receptors, Adrenergic, beta / drug effects*
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Receptors, Serotonin / drug effects
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Serotonin / physiology*
Substances
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Adrenergic beta-Antagonists
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Antidepressive Agents
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Imidazoles
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Neurotransmitter Uptake Inhibitors
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Piperidines
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Propanolamines
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Receptors, Adrenergic, beta
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Receptors, Serotonin
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Amitriptyline
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Serotonin
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Paroxetine
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CGP 20712A
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CGP 12177