[Hemodynamic profile of 8-OH-DPAT and 5-HT1 agonists in the anesthetized dog].
In anaesthetized dogs, intravenous administration of 8-OH-DPAT (1-300 micrograms/kg i.v.) induced dose-dependent decrease in blood pressure (BP) and total peripheral resistance (TPR). Heart rate (HR) and cardiac output (CO) changed little. 5-Carboxamidotryptamine (5-CT) (0.3-3 micrograms/kg i.v.) dose-dependently decreased BP and TPR but increased HR, CO, myocardial contractility and pulmonary arterial pressure (PAP). 5-MeODMT and RU 24969 decreased BP only after the highest dose used (300 micrograms/kg i.v. and 1 mg/kg i.v. respectively) but significantly increased PAP at all doses used. These results indicated that in dogs as in other animal species, 8-OH-DPAT decreases BP by systemic vasodilatation without a reflex activation of the myocardium. This lack of a reflex tachycardia suggests a centrally-mediated effects of 8-OH-DPAT. In contrast to 8-OH-DPAT, the vasodilatation induced by 5-CT triggers a reflex tachycardia. The increase in PAP induced by 5-MeODMT, RU 24969 and--to a lesser extent--5-CT, may be due to a direct stimulation of 5-HT2 receptors. However, a 5-HT1 component could not be ruled out.
Dabire
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INSERM U 228, faculté de médecine Broussais Hôtel-Dieu, Paris, France.
Cherqui
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Schmitt
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D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000704:Analysis of Variance; D000768:Anesthesia, General; D000818:Animals; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D007211:Indoles; D008732:Methoxydimethyltryptamines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; C025145:5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C047087:5-carboxamidotryptamine
Profil hémodynamique du 8-OH-DPAT et des agonistes 5-HT1 chez le chien anesthésié.