Central 5-HT and the respiratory response to acoustic stimulation in awake rats: effects of PCPA, 5-HTP and 8-OH-DPAT.
It was found that PCPA (4 X 50-100 mg/kg) decreased the respiratory response to tone pulses (acoustic reaction), and this effect was antagonized by the administration of 5-HTP (25 mg/kg), after inhibition of extracerebral aromatic amino acid decarboxylase by means of benserazide (25 mg/kg). A further increase in the dose of 5-HTP, 50-100 mg/kg, in animals not treated with PCPA did not significantly affect the acoustic reaction. The putative 5-HT agonist 8-OH-DPAT produced a decrease in the acoustic reaction (but also at higher doses some desynchronization of respiration with tone). The administration of d-amphetamine, 0.5-2.0 mg/kg, resulted in an increase in the acoustic reaction. Thus, in the present experiment, using a simple sensory-motor response, 8-OH-DPAT behaves as a 5-HT antagonist and the results provide further support for mixed 5-HT receptor agonist/antagonist properties of this compound.
Ahlenius
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Criborn
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Henriksson
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D006916:5-Hydroxytryptophan / Q000494:pharmacology; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000161:Acoustic Stimulation; D000818:Animals; D002490:Central Nervous System / Q000502:physiology*; D003913:Dextroamphetamine / Q000494:pharmacology; D010134:Fenclonine / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000502:physiology*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D013764:Tetrahydronaphthalenes; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D006916:5-Hydroxytryptophan; D010134:Fenclonine; D003913:Dextroamphetamine