An inhibitory role for brain serotonin-containing systems in the locomotor effects of d-amphetamine.
Locomotor activity induced by d-amphetamine was found to be potentiated by food deprivation, a tryptophan-free diet, p-chlorophenylalanine and drugs proposed to antagonize serotonin receptors in brain. Administration of L-tryptophan 1 hour prior to d-amphetamine injection was found to antagonize the enhanced response to d-amphetamine in starved rats and in rats which had tryptophan removed from their diet. However, tryptophan did not block the potentiated response to d-amphetamine in animals pretreated with p-chlorophenylalanine. These findings suggested that the antagonism of d-amphetamine-induced activity by tryptophan in starved rats and rats fed a tryptophan-free diet was not due to a nonspecific depressant effect of the amino acid. Since accumulation of d-amphetamine and its metabolites was not affected by any of the treatments which enhanced its activity, it seems unlikely that an alteration in the metabolism of d-amphetamine can explain these findings. The present work provides additional support for the view that serotonergic fibers play an important role in the actions of d-amphetamine.
Duke Scholars
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Related Subject Headings
- Tryptophan
- Stimulation, Chemical
- Serotonin
- Rats
- Probenecid
- Pharmacology & Pharmacy
- Pargyline
- Motor Activity
- Male
- Hydroxyindoleacetic Acid
Citation
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Tryptophan
- Stimulation, Chemical
- Serotonin
- Rats
- Probenecid
- Pharmacology & Pharmacy
- Pargyline
- Motor Activity
- Male
- Hydroxyindoleacetic Acid