Modulation of the vagal bradycardia evoked by stimulation of upper airway receptors by central 5-HT_1 receptors in anaesthetized rabbits

摘要

The effects of central application of 5-HT_1A and 5-HT_1B/1D receptor ligands n the reflex bradycardia, apnoea, renal sympathoexcitation and pressor response evoked by stimulating upper airway receptors with smoke in atenolol-pretreated anaesthetized rabbits were studied. Intracisternal administration of the 5-HT_1A receptor antagonists WAY-100635(100 μg kg~-1) and (-)pindolol(100 μg kg~-1) significantly reduced the smoke-induced bradycardia, attenuated the pressor response and in the case of (-)piondolol, sympathetic nerve activity. The same dose of WAY-100635 i.v. was without effect.