Evidence for the ability of central 5-HT1A receptors to modulate the vagal bradycardia induced by stimulating the upper airways of anesthetized rabbits with smoke.
Cigarette smoke passed through the nasal cavity of atenolol pre-treated anesthetized spontaneously breathing rabbits caused a bradycardia which was significantly modified by intracisternal application of the 5-HT1A receptor ligands 8-OH-DPAT (50 micrograms.kg-1) and buspirone (200 micrograms.kg-1). 8-OH-DPAT attenuated while buspirone potentiated the bradycardia. These results support the view that 5-HT1A receptors play an important role in modulating the excitability of cardiac vagal motoneurones.
Futuro-Neto
H A
HA
Departamento de Ciencias Fisiologicas, Universidade Federal Do Espirito Santo, Vitoria ES, Brazil.
Pires
J G
JG
Gilbey
M P
MP
Ramage
A G
AG
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001049:Apnea / Q000139:chemically induced / Q000503:physiopathology; D001262:Atenolol / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002065:Buspirone / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D007276:Injections, Intraventricular; D007668:Kidney / Q000187:drug effects / Q000294:innervation; D009046:Motor Neurons / Q000187:drug effects; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012907:Smoking / Q000503:physiopathology*; D013268:Stimulation, Chemical; D014630:Vagus Nerve / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
D011985:Receptors, Serotonin; D001262:Atenolol; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D002065:Buspirone