Effects of B-HT 920 in the tail-suspension test.
The effect of B-HT 920 on mice subjected to the tail-suspension test (TST), a behavioural tool for gauging depression, was studied. During the test, all the animals had bouts of agitation interspersed with periods of immobility but B-HT 920-treated animals exhibited a differentiated behavioural pattern according to the dose employed: at doses selective for dopaminergic (DA) autoreceptor stimulation (50 and 100 micrograms/kg), the periods of immobility were unaffected, while at higher doses (0.5, 1, 2 and 3 mg/kg), which are also considered to be active on alpha 2-adrenoceptors, they were much shorter, as they are when known antidepressants are administered. Both clonidine (75 and 150 micrograms/kg) and yohimbine (1 and 5 mg/kg), alpha 2-adrenoceptor agonist and antagonist, respectively, increased immobility time, while N-n-propylnorapomorphine, a DA-agonist, at a dose (10 micrograms/kg) specific for DA autoreceptors, was completely ineffective. Since the behavioural effects of B-HT 920 vary according to the dosage employed, discussion centres on what receptors might conceivably underly these effects and on their preclinical relevance.
Institute of Pharmacology, University of Modena, Italy.
F
F
Ferrari
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M
Cassinadri
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PL
Tartoni
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A
Tampieri
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology*; D003000:Clonidine / Q000494:pharmacology; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D015259:Dopamine Agents / Q000494:pharmacology*; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D015016:Yohimbine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D001381:Azepines; D015259:Dopamine Agents; D015016:Yohimbine; C009074:N-n-propylnorapomorphine; C024763:talipexole; D003000:Clonidine; D001058:Apomorphine; D007099:Imipramine