Alpha-adrenergic bronchoconstriction in man.
In normal as well as in asymptomatic subjects, inhaled norepinephrine (NE) induced bronchoconstriction and respiratory asynchronism only after pretreatment by propranolol. However, lower doses of beta-receptor blocker were needed in asthmatics to reveal NE constrictive properties. These airways resistance increases were prevented by phentolamine. These pharmacological data indicate that the resting bronchial tone is relaxed permanently by beta-adrenergic receptors stimulation whose suppression unmasks alpha-induced constriction. Bronchial relaxing properties predominate normally in man and in guinea pigs, as previously demonstrated (Marcelle, 1996).
Marcelle
R
R
Institut Léon Fredericq, Physiologie, Université de Liège, Belgium.
D000280:Administration, Inhalation; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D000403:Airway Resistance / Q000187:drug effects; D001249:Asthma / Q000503:physiopathology*; D016084:Bronchoconstriction / Q000187:drug effects*; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology; D010646:Phentolamine / Q000008:administration & dosage / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D011942:Receptors, Adrenergic, alpha; D011433:Propranolol; D009638:Norepinephrine; D010646:Phentolamine