Attenuation by electroconvulsive shock and antidepressant drugs of the 5-HT1A receptor-mediated hypothermia and serotonin syndrome produced by 8-OH-DPAT in the rat.
The hypothermia and motor behavioural syndrome produced in rats by injection of the 5-HT1A ligand 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) has been studied following administration of electroconvulsive shock under halothane anaesthesia (ECS) and during the administration of antidepressant drugs. Repeated ECS attenuated the hypothermic response to 8-OH-DPAT (0.1 mg/kg SC) immediately after the last of five shocks given spread out over 10 days with a maximal effect 21 days after the final shock. A single ECS was without effect. The serotonin syndrome produced by 8-OH-DPAT (0.75 mg/kg SC) was also attenuated, although simple motility was increased. Zimeldine (20 mg/kg) and desipramine (20 mg/kg), when given once daily for 14 days also attenuated the hypothermia and the serotonin syndrome provoked by 8-OH-DPAT. The hypothermic response was somewhat reduced 24 h after a single injection of zimeldine but not 45 min after zimeldine (5 mg/kg IP). At a high dose (20 mg/kg) tranylcypromine clearly attenuated both responses 24 h after a single injection. Tranylcypromine (6 mg/kg IP) showed a smaller effect after a single injection but attenuated the behavioural syndrome on repeated administration. Repeated injection of flurazepam (10 mg/kg IP) was without effect on either the behavioural or hypothermic response to 8-OH-DPAT. These findings are consistent with the view that responses mediated via the 5-HT1A receptor may be involved in the mechanism of action of antidepressant treatments.
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001831:Body Temperature / Q000187:drug effects*; D004597:Electroshock; D005479:Flurazepam / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009281:Naphthalenes / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000502:physiology*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*; D014191:Tranylcypromine / Q000494:pharmacology
D000928:Antidepressive Agents; D009281:Naphthalenes; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D012701:Serotonin; D014191:Tranylcypromine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D005479:Flurazepam