title: LTD4-induced bronchoconstriction in patients with asthma: lack of a vagal reflex.
abstract: The mechanism by which leukotriene D4 (LTD4) induces bronchoconstriction in man is unclear. We have investigated this mechanism by examining the effect of nedocromil sodium and ipratropium bromide on LTD4-induced bronchoconstriction in six mild asthmatic patients. The bronchoconstrictor response to increasing concentrations of inhaled LTD4 (0.08 to 100 nmol) was assessed by measuring changes in respiratory resistance (Rrs) at 6 Hz by the forced oscillation method. Results were expressed as the provocative dose causing 100% increase in Rrs (PD100). Neither nedocromil (4 mg) nor ipratropium (0.8 mg) showed significant effect on LTD4-induced bronchoconstriction in asthmatic subjects. These results suggest that in asthmatics LTD4-induced bronchoconstriction is unlikely to involve vagal reflexes.
authors.affiliation: Department of Clinical Pharmacology, Royal Postgraduate Medical School, London.
authors.forename: L E
authors.initials: LE
authors.lastname: Ayala
authors.forename: N B
authors.initials: NB
authors.lastname: Choudry
authors.forename: R W
authors.initials: RW
authors.lastname: Fuller
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000187:drug effects*; D006801:Humans; D009241:Ipratropium / Q000494:pharmacology; D008297:Male; D017835:Nedocromil; D015363:Quinolones / Q000494:pharmacology; D012018:Reflex / Q000187:drug effects*; D012129:Respiratory Function Tests; D013189:SRS-A / Q000494:pharmacology*; D014630:Vagus Nerve / Q000187:drug effects*
chemical_list: D015363:Quinolones; D013189:SRS-A; D017835:Nedocromil; D009241:Ipratropium