In vivo demonstration of alpha-2-adrenoceptor-mediated inhibition of the excitatory non-cholinergic neurotransmission in guinea pig airways.
In anaesthetized guinea pigs, vagal nerve stimulation caused an atropine- and hexamethonium-resistant increase in the respiratory insufflation pressure. Clonidine (0.05 mg/kg i.v.) inhibited the increase in insufflation pressure caused by vagal stimulation. This effect of clonidine was antagonized by the alpha-2-antagonist yohimbine (0.5 mg/kg i.v.), but not by the alpha-1-antagonist prazosin (0.03 mg/kg i.v.). In conclusion, the increase in the respiratory insufflation pressure, caused by stimulation of noncholinergic nerves, seemed to be controlled by inhibitory alpha-2-adrenoceptors in guinea pig airways.
Grundström
N
N
Andersson
R G
RG
D000109:Acetylcholine / Q000494:pharmacology; D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D006168:Guinea Pigs; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D011312:Pressure; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D012119:Respiration; D009435:Synaptic Transmission; D014132:Trachea / Q000294:innervation*; D014630:Vagus Nerve / Q000502:physiology
D006584:Hexamethonium Compounds; D011942:Receptors, Adrenergic, alpha; D001285:Atropine; D003000:Clonidine; D000109:Acetylcholine