No involvement of 5-HT(7) or 5-HT(1D) receptors in the (R)-8-OH-DPAT-induced depression of the monosynaptic reflex in spinalized rats.
(R)-8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) depressed the monosynaptic reflex. This effect was not antagonized by 5-HT(1A) receptor antagonists. We examined whether 5-HT(1D) and 5-HT(7) receptors are involved in (R)-8-OH-DPAT-induced inhibition of the monosynaptic reflex in spinalized rats. Pretreatment with methiothepin and mesulergine, but not clozapine, inhibited (R)-8-OH-DPAT-induced monosynaptic reflex depression. Pretreatment with 2a-(4-phenyl-1,2,3,6-tetrahydropyridal)butyl)-2a,3,4,5-tetrahydrobenzo[c,d]indol-2(1H)-one (DR4004) and (R)-1-[(3-hydroxyphenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrolidine (SB-269970), new selective 5-HT(7) receptors antagonists, and N-[methoxy-3-(4-methyl-l-piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)[1,1-biphenyl]-4-carboxamide (GR127935), a selective 5-HT(1D) receptor antagonist, had no effect on (R)-8-OH-DPAT-induced depression. These results suggested that 5-HT(7) and 5-HT(1D) receptors are not involved in (R)-8-OH-DPAT-induced monosynaptic reflex depression.
Honda
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M
Laboratory of CNS Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho, Nagoya 467-8603, Japan. honda@phar.nagoya-cu.ac.jp
Ono
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D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D003024:Clozapine / Q000494:pharmacology; D003655:Decerebrate State; D004305:Dose-Response Relationship, Drug; D004873:Ergolines / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008719:Methiothepin / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D044346:Receptor, Serotonin, 5-HT1D; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012023:Reflex, Monosynaptic / Q000187:drug effects* / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors
C117652:2a-(4-phenyl-1,2,3,6-tetrahydropyridyl)cyclohex(a-3,4)indole-2-one; D004873:Ergolines; D007211:Indoles; D010069:Oxadiazoles; D010636:Phenols; D010879:Piperazines; D011725:Pyridines; D044346:Receptor, Serotonin, 5-HT1D; D011985:Receptors, Serotonin; C404922:SB 269970; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D013449:Sulfonamides; C104425:serotonin 7 receptor; C090701:GR 127935; D008719:Methiothepin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D003024:Clozapine; C031649:mesulergine