[Differences between the effects of indorenate and other 5-HT1A agonists on the rabbit aorta].
The aim of this study was to determine if like buspirone, ipsapirone and 8-hydroxy-2(di-N-propylamino)tetralin (8-OH-DPAT), the alpha 1-adrenoceptors are involved in the responses elicited by indorenate in rabbit aorta. Exception made of ipsapirone, all the 5-HT1A agonists above mentioned contracted aortic rings. The contraction elicited by buspirone and 8-OH-DPAT was blocked with prazosin (alpha 1-adrenergic antagonist), whereas the effect of indorenate was unaffected with this blocker but it was inhibited with ritanserin (5-HT2 antagonist). On the other hand, buspirone, ipsapirone and 8-OH-DPAT but not indorenate relaxed arteries precontracted with methoxamine (alpha 1-adrenergic agonist) and none of the agonists relaxed preparations precontracted with acetylcholine or KCl. The results indicate that buspirone and 8-OH-DPAT are partial alpha 1-adrenoceptor agonists since they elicited contractions which are blocked with prazosin and relaxed only rings precontracted with methoxamine. Ipsapirone behaved as an alpha 1-adrenoceptor antagonist since it showed the relaxant but not the contractile effect. Finally, we found no evidence that indorenate has afinity for alpha 1-adrenoceptors. Contraction elicited by this agonist seems to be mediated by 5-HT2 receptors, inasmuch it was blocked with ritanserin.
Castillo
C
C
Departamento de Fisiología y Farmacología, Escuela Superior de Medicina, I.P.N., México, D.F.
Rosas-Lezama
M A
MA
Castillo
E F
EF
Larios
F J
FJ
Hong
E
E
D008735:5-Methoxytryptamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D008735:5-Methoxytryptamine; C033600:indorenate
Diferencias entre los efectos del indorrenato y otros agonistas 5-HT1A en la aorta de conejo.