title: Albuterol does not antagonize the inhibitory effect of dexamethasone on monocyte cytokine release.
abstract: Beta2-adrenoceptor agonists given by the inhaled route are the most effective bronchodilators known, yet high doses of these drugs may be associated with an increase in asthma mortality and morbidity. One theory for this paradox is that chronic use of beta2-adrenoceptor agonists compromises the anti-inflammatory action of glucocorticosteroids. This hypothesis derives from the ability of albuterol and fenoterol to inhibit the interaction of the glucocorticosteroid receptor (GR) with proinflammatory transcriptional activators acting on the promoter region of certain target genes that encode cytokines such as tumor necrosis factor-alpha (TNF alpha) and granulocyte/macrophage colony-stimulating factor (GM-CSF). However, the functional relevance of these results has not been formally investigated. We have tested the hypothesis that albuterol reduces the ability of dexamethasone to inhibit the generation of TNF alpha and GM-CSF from lipopolysaccharide (LPS)-stimulated human monocytes. Pretreatment of human monocytes with albuterol (1 and 100 microM) for 5 and for 180 min inhibited maximally TNF alpha generation by approximately 25%. However, regardless of the concentration of albuterol, or the time of preincubation, the inhibitory effect of dexamethasone was not significantly affected with respect to the EC50 or the maximal effect produced. Qualitatively identical data were obtained when GM-CSF release was used as an index of monocyte activation. We conclude that high concentrations of albuterol do not compromise the ability of dexamethasone to suppress the generation of TNF alpha and GM-CSF from LPS-stimulated human monocytes.
authors.affiliation: Thoracic Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, London, United Kingdom.
authors.forename: P M
authors.initials: PM
authors.lastname: Seldon
authors.forename: D A
authors.initials: DA
authors.lastname: Stevens
authors.forename: I M
authors.initials: IM
authors.lastname: Adcock
authors.forename: B J
authors.initials: BJ
authors.lastname: O'Connor
authors.forename: P J
authors.initials: PJ
authors.lastname: Barnes
authors.forename: M A
authors.initials: MA
authors.lastname: Giembycz
mesh_terms: D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002478:Cells, Cultured; D016207:Cytokines / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000187:drug effects / Q000235:genetics; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology; D016018:Least-Squares Analysis; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors; D012044:Regression Analysis; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000235:genetics
chemical_list: D000318:Adrenergic beta-Agonists; D000893:Anti-Inflammatory Agents; D001993:Bronchodilator Agents; D016207:Cytokines; D005938:Glucocorticoids; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D011965:Receptors, Glucocorticoid; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D000420:Albuterol