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Adenosine-induced bronchoconstriction in asthma. Antagonism by inhaled theophylline.
Am Rev Respir Dis. 1984 Mar; 129(3):380-4.AR

Abstract

Inhaled adenosine causes bronchoconstriction in asthmatic patients. Antagonism of the bronchoconstrictor effect of endogenous adenosine has been proposed as a possible mechanism of action of theophylline in asthma. To directly investigate this, we have compared the airway responses to inhaled adenosine and histamine, with and without the prior administration of inhaled theophylline in 8 allergic asthmatic subjects. Airway response was measured both as forced expiratory volume in one second (FEV1) and as specific airway conductance (SGaw). Inhaled adenosine was less potent than histamine in producing bronchoconstriction, with geometric mean concentrations required to produce a 20% fall of FEV1 (PCf20) and a 40% fall of SGaw (PCs40) being 0.27 and 0.25 mg/ml for adenosine and 0.10 and 0.09 mg/ml for histamine. In a total nebulized dose of 37.5 mg, inhaled theophylline was a weak bronchodilator that caused maximal increases in FEV1 of 2 +/- 2% (mean +/- SE, p less than 0.05) and in SGaw of 8 +/- 4% (p greater than 0.05). However, theophylline significantly inhibited adenosine-induced bronchoconstriction, increasing the PCf20 and PCs40 values for adenosine to 1.66 (p less than 0.001) and 2.34 (p less than 0.005) mg/ml, respectively. Inhibition of histamine-induced bronchoconstriction was less marked, with PCf20 and PCs40 values of 0.19 (p greater than 0.05) and 0.21 (p less than 0.05) mg/ml. Thus, adenosine is a bronchoconstrictor in asthma whose effects are preferentially antagonized by concentrations of theophylline that cause little change in baseline airway caliber.(

ABSTRACT

TRUNCATED AT 250 WORDS)

Authors

No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

6703496

Citation

Cushley, M J., et al. "Adenosine-induced Bronchoconstriction in Asthma. Antagonism By Inhaled Theophylline." The American Review of Respiratory Disease, vol. 129, no. 3, 1984, pp. 380-4.
Cushley MJ, Tattersfield AE, Holgate ST. Adenosine-induced bronchoconstriction in asthma. Antagonism by inhaled theophylline. Am Rev Respir Dis. 1984;129(3):380-4.
Cushley, M. J., Tattersfield, A. E., & Holgate, S. T. (1984). Adenosine-induced bronchoconstriction in asthma. Antagonism by inhaled theophylline. The American Review of Respiratory Disease, 129(3), 380-4.
Cushley MJ, Tattersfield AE, Holgate ST. Adenosine-induced Bronchoconstriction in Asthma. Antagonism By Inhaled Theophylline. Am Rev Respir Dis. 1984;129(3):380-4. PubMed PMID: 6703496.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Adenosine-induced bronchoconstriction in asthma. Antagonism by inhaled theophylline. AU - Cushley,M J, AU - Tattersfield,A E, AU - Holgate,S T, PY - 1984/3/1/pubmed PY - 1984/3/1/medline PY - 1984/3/1/entrez SP - 380 EP - 4 JF - The American review of respiratory disease JO - Am Rev Respir Dis VL - 129 IS - 3 N2 - Inhaled adenosine causes bronchoconstriction in asthmatic patients. Antagonism of the bronchoconstrictor effect of endogenous adenosine has been proposed as a possible mechanism of action of theophylline in asthma. To directly investigate this, we have compared the airway responses to inhaled adenosine and histamine, with and without the prior administration of inhaled theophylline in 8 allergic asthmatic subjects. Airway response was measured both as forced expiratory volume in one second (FEV1) and as specific airway conductance (SGaw). Inhaled adenosine was less potent than histamine in producing bronchoconstriction, with geometric mean concentrations required to produce a 20% fall of FEV1 (PCf20) and a 40% fall of SGaw (PCs40) being 0.27 and 0.25 mg/ml for adenosine and 0.10 and 0.09 mg/ml for histamine. In a total nebulized dose of 37.5 mg, inhaled theophylline was a weak bronchodilator that caused maximal increases in FEV1 of 2 +/- 2% (mean +/- SE, p less than 0.05) and in SGaw of 8 +/- 4% (p greater than 0.05). However, theophylline significantly inhibited adenosine-induced bronchoconstriction, increasing the PCf20 and PCs40 values for adenosine to 1.66 (p less than 0.001) and 2.34 (p less than 0.005) mg/ml, respectively. Inhibition of histamine-induced bronchoconstriction was less marked, with PCf20 and PCs40 values of 0.19 (p greater than 0.05) and 0.21 (p less than 0.05) mg/ml. Thus, adenosine is a bronchoconstrictor in asthma whose effects are preferentially antagonized by concentrations of theophylline that cause little change in baseline airway caliber.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 0003-0805 UR - https://www.unboundmedicine.com/medline/citation/6703496/Adenosine_induced_bronchoconstriction_in_asthma__Antagonism_by_inhaled_theophylline_ L2 - https://www.atsjournals.org/doi/10.1164/arrd.1984.129.3.380?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -