Facilitation of 8-OHDPAT-induced forepaw treading of rats by the 5-HT2 agonist DOI.
The potency of the serotonin 1A (5-HT1A) agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OHDPAT), to induce forepaw treading was increased 20-fold after co-treatment with the 5-HT2 agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI). DOI induced head twitches which were inhibited by 8-OHDPAT. The putative 5-HT1B agonist, 1-(3-trifluoromethylphenyl)piperazine (TFMPP), had a weak effect on the responses to DOI or 8-OHDPAT. The forepaw treading induced by 8-OHDPAT plus DOI was inhibited by high doses of (-)-alprenolol, ketanserin or ritanserin, but was not influenced by the beta-adrenoceptor antagonist, ICI 118.551, or the 5-HT3 antagonist, ICS 205-930. A non-effective dose of (-)-alprenolol increased the inhibitory effect of ketanserin and ritanserin. These results indicate a complex and different interaction between 5-HT1A and 5-HT2 receptors in the expression of two behavioural responses mediated by 5-HT.
Arnt
J
J
Department of Pharmacology, H. Lundbeck A/S, Copenhagen, Denmark.
Hyttel
J
J
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000526:Alprenolol / Q000494:pharmacology; D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D007279:Injections, Subcutaneous; D007650:Ketanserin / Q000378:metabolism; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D016713:Ritanserin; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D000662:Amphetamines; D009281:Naphthalenes; D010880:Piperidines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D016713:Ritanserin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000526:Alprenolol; D007650:Ketanserin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine