Comparison of effects of some 5-HT1 agonists on blood pressure and heart rate of normotensive anaesthetized rats.
The present experiments served to compare the effects of the 3 5-HT1 agonists, 8-OH-DPAT, 5-MeODMT and TFMPP on the blood pressure and heart rate of normotensive anaesthetized rats. All the agonists induced, after i.v. injection, a decrease in blood pressure and heart rate. The hypotensive effects of 5-MeODMT and TFMPP were preceded by an increase, suppressed by both ketanserin and methysergide. The decrease in blood pressure induced by 5-MeODMT and 8-OH-DPAT was not antagonized by ketanserin, cocaine (and methysergide for 8-OH-DPAT) but was antagonized by methysergide (for 5-MeODMT) and spiroxatrine (for both). Bradycardia was not susceptible to ketanserin and cocaine (for 5-MeODMT) or to ketanserin and methysergide (for 8-OH-DPAT) but to methysergide and spiroxatrine (for 5-MeODMT) and cocaine and spiroxatrine (for 8-OH-DPAT). These results suggested that the hypotension and bradycardia induced by 5-MeODMT and 8-OH-DPAT are due to the stimulation of '5-HT1-like' receptors and probably to the 5-HT1A subtype; the 5-MeODMT-induced hypertension being ascribed to the stimulation of 5-HT2 receptors.
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D008732:Methoxydimethyltryptamines; D010879:Piperazines; D012702:Serotonin Antagonists; D013764:Tetrahydronaphthalenes; C018406:1-(3-trifluoromethylphenyl)piperazine; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin