PT  - JOURNAL ARTICLE
AU  - N Crimi
AU  - F Palermo
AU  - R Oliveri
AU  - R Polosa
AU  - I Settinieri
AU  - A Mistretta
TI  - Protective effects of inhaled ipratropium bromide on bronchoconstriction induced by adenosine and methacholine in asthma
AID  - 10.1183/09031936.93.05050560
DP  - 1992 May 01
TA  - European Respiratory Journal
PG  - 560--565
VI  - 5
IP  - 5
4099  - http://erj.ersjournals.com/content/5/5/560.short
4100  - http://erj.ersjournals.com/content/5/5/560.full
SO  - Eur Respir J1992 May 01; 5
AB  - Although adenosine-induced bronchoconstriction is mainly due to mast cell mediator release, vagal reflexes have also been implicated in this response. We have investigated the effect of a specific muscarinic-receptor antagonist, ipratropium bromide, on methacholine- and adenosine-induced bronchoconstriction in a randomized, placebo-controlled, double-blind study of 12 asthmatic subjects. Airway response was evaluated as forced expiratory volume in one second (FEV1). Inhaled ipratropium bromide (40 micrograms), administered 20 min prior to bronchoprovocation, increased the provocation dose of inhaled methacholine and adenosine required to reduce FEV1 by 20% from baseline (PD20) from 0.11 to 0.79 mg (p less than 0.01) and from 0.57 to 1.27 mg (p less than 0.01), respectively. The mean baseline FEV1 values after administration of ipratropium bromide were significantly higher than after placebo administration (p less than 0.05). However, there was no correlation between the degree of bronchodilatation and dose-ratios for methacholine and adenosine. The findings of the present study implicate vagal reflexes in the bronchospastic response induced by inhaled adenosine in asthma.