title: The effect of inhaled ouabain on bronchomotor tone and histamine responsiveness in asthmatic patients.
abstract: We have studied the effect of inhaled ouabain on resting bronchomotor tone and histamine responsiveness in eight asthmatic patients in an attempt to clarify the role of Na/K ATPase in airway reactivity. Doses ranged from 50 micrograms to 5000 micrograms and were given in a placebo controlled, double blind manner. Baseline FEV1 was recorded prior to inhalation and at intervals up to 30 min thereafter. At 30 min, a histamine provocation test was performed and results expressed as that concentration producing a 20% fall in FEV1. Maximum fall in FEV1 was not significantly different between placebo or any dose of ouabain, ranging from 4.3%-8.2% (p greater than 0.06) nor was histamine reactivity altered significantly (geometric mean range 0.17 mg-0.29 mg [p greater than 0.2]). Unlike animal studies therefore, we have been unable to demonstrate any effect of Na/K ATPase inhibition on airway reactivity in vivo.
authors.affiliation: Department of Respiratory Medicine, Western Infirmary, Glasgow, UK.
authors.forename: G
authors.initials: G
authors.lastname: Hulks
authors.forename: K R
authors.initials: KR
authors.lastname: Patel
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006633:Histamine Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010042:Ouabain / Q000008:administration & dosage / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D006633:Histamine Antagonists; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase