Involvement of brain 5-HT1A receptors in the hypotensive response to urapidil
| Autor: | Norbert Kolassa, Klaus-Dieter Beller, Karl H. Sanders |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Male
Agonist Tetrahydronaphthalenes medicine.drug_class Drug Evaluation Preclinical Blood Pressure Stimulation Femoral artery Urapidil Piperazines Dioxanes chemistry.chemical_compound Heart Rate medicine.artery Animals Medicine Spiro Compounds Infusions Intravenous Adrenergic alpha-Antagonists Antihypertensive Agents 8-Hydroxy-2-(di-n-propylamino)tetralin Dose-Response Relationship Drug business.industry Chloralose Receptor antagonist Blood pressure Spiroxatrine chemistry Receptors Serotonin Anesthesia Cats Female Cardiology and Cardiovascular Medicine business Brain Stem |
| Zdroj: | The American Journal of Cardiology. 64:D7-D10 |
| ISSN: | 0002-9149 |
| Popis: | Stimulation of serotonin-1A (5-hydroxytryptamine) (5-HT1A) receptors in the brain stem has been suggested to contribute to the antihypertensive action of the alpha 1-adrenoceptor antagonist urapidil. This hypothesis was tested by analyzing the influence of the 5-HT1A receptor antagonist spiroxatrine on the hypotensive responses to urapidil and the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT). Chloralose/urethane-anesthetized cats underwent thoracotomy and were artificially ventilated. Blood pressure was monitored in the femoral artery. Urapidil (0.01 to 10 mumol/kg) or 8-OH-DPAT (3 to 30 nmol/kg) was injected into a femoral vein and the maximal hypotensive response recorded. A dose-response test with both drugs was performed before and after administration of spiroxatrine (3 and 10 nmol/kg); the latter was given through the vertebral artery, thus delivering the antagonist to the brain stem. Blood pressure was dose-dependently reduced by urapidil and 8-OH-DPAT after intravenous injection. Central administration of spiroxatrine through the vertebral artery shifted the dose-response curves of both drugs markedly and in a dose-dependent manner to the right, while the hypotensive response to the peripheral vasodilator nitroglycerin remained unchanged. The results suggest that the hypotensive response after peripheral administration of urapidil is mediated in part by stimulation of brain 5-HT1A receptors and this effect on central cardiovascular regulation is additive to the blood pressure reduction resulting from peripheral alpha-adrenoceptor blockade. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|