DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Bromotyrosines in sputum proteins and treatment effects of terbutaline and budesonide in asthma.

Author(s): van Dalen CJ, Aldridge RE, Chan T, Senthilmohan R, Hancox RJ, Cowan JO, Taylor DR, Town GI, Kettle AJ

Affiliation(s): Centre for Public Health Research, Massey University, Wellington, New Zealand. c.j.vandalen@massey.ac.nz

Publication date & source: 2009-10, Ann Allergy Asthma Immunol., 103(4):348-53.

Publication type: Randomized Controlled Trial; Research Support, Non-U.S. Gov't

BACKGROUND: Inhaled corticosteroids are widely used in the treatment of persistent asthma, usually combined with inhaled beta2-agonists. Previous research suggests that short-acting beta2-agonists (SABAs) may downregulate the anti-inflammatory effects of inhaled corticosteroids, thereby increasing asthma morbidity. OBJECTIVE: To determine whether 3-bromotyrosine and 3,5-dibromotyrosine levels, specific markers of eosinophil activation, reflect treatment effects on airway inflammation of inhaled corticosteroids and SABAs and support previous conclusions. METHODS: Levels of 3-bromotyrosine and 3,5-dibromotyrosine were measured in sputum supernatants using stable isotope dilution gas chromatography-mass spectrometry in a randomized, placebo-controlled, crossover study of treatment with terbutaline, budesonide, and their combination in patients with persistent asthma. Thirty-four individuals were randomized, and 28 completed the study. RESULTS: Treatment with budesonide lowered median 3-bromotyrosine levels compared with treatment with placebo, terbutaline, and budesonide-terbutaline (0.24 vs 0.64, 0.62, and 0.43 3-bromotyosine/tyrosine [mmol/mol]; P < .05) and lowered median 3,5-dibromotyrosine levels compared with placebo and terbutaline treatments (0.04 vs 0.11 and 0.07 3,5-dibromotyrosine/ tyrosine [mmol/mol], P < .05). Unlike eosinophil numbers, 3-bromotyrosine and 3,5-dibromotyrosine levels did not increase with terbutaline treatment compared with placebo treatment but were significantly raised when terbutaline was added to budesonide treatment. 3-Bromotyrosine levels correlated significantly with eosinophil cationic protein levels in all groups. CONCLUSIONS: 3-Bromotyrosine and 3,5-dibromotyrosine levels reflect treatment effects in asthma and support previous findings that SABAs impair the anti-inflammatory effects of inhaled corticosteroids. In addition to eosinophil numbers and eosinophil cationic protein levels, these modified tyrosine residues provide useful information about the inflammatory state of the airways.

Page last updated: 2010-10-05

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017