Urinary N-methylhistamine and sulfidopeptide leukotriene in exercise-induced asthma / 천식및알레르기

BACKGROUND: Exercise can aggravate asthmatic symptoms in many patients with bronchial asthma. It is caused by that inhaled air bypasses nasal cavity and goes directly to the lower airways through open mouth dring exercise. Although the pathogenetic mechanisms of exercise-induced asthma(EIA) have not been clarified yet, there is evidence that chemical mediators, released from the inflammatory cells triggered by airway cooling or drying, might be responsible for induction of bronchoconstriction. However, it has been controversial which chemical mediators or cells are involved in such process. Objectiye . The aim of this study was to evaluate the role of activated mast cells in the pathogenesis of EIA and find out whether or not sulfidopeptide leukotrienes (LTC4/d4/E4) are involved in the exercise-induced bronchoconstriction. MATERIAL AND METHOD: Eleven asthmatics with documented exercise-induced bronchoconstriction and 10 control subjects were studied. Before and 6 hours after free running for 6 minutes, forced expiratory volume in 1 second (FEV,) and the concentrations of N- methylhistamine, LTE4, and creatinine in unine collected for 6 hours after exercise were determined. RESULT: Urinary concentrations of N-methylhistamine(mean+SE, ng/mg creatinine) of EIA patients before and after exercise were 159+40 and 450+75, respectively. Those of control subjects were 208+ 54 and 275+ 62, respectively. Uninary N-methylhistamine levels of EIA group increased significantly after exercise, while those of control group did not change. Urinary concentrations of LTE,(mean+SE, pg/mg creatinine) of EIA patients before and after exercise were 15.6 k2.6 and 22.2+5.8, respectively. Those of control subjects were 10.4+ 4.0, 18.2 +7.0, respectively. The concentrations of LTE4 in the urine samples collected before exerise revealed no difference between EIA and control subjects (p=0.07). There was no change after exercise in both groups. Percent fall of FEV, was 29.1+8.0% (mean+SD) in EIA group and 3.4 + 4.0% in control group, respectively. There was no correlation between reduction of FEV, and change in urinary concentrations of N-methyl-histmine after exercise. CONCLUSTION: Chemical mediators of activated mast cells may be involved in exercise-induced bronchoconstriction, but there is little evidence for enhanced sulfidopeptide leukotriene generation as assessed by urinary LTE4.

Metered dose inhaler(MDI)-induced bronchocostriction in asthmatic patients: the effects of the incert ingredients and propellants / 천식및알레르기

BACKGROUND: Bronchoconstriction associated with aerosolized agents delivered by a metered dose inhaler (MDI) is relatively uncommon, but has been of particular interest. MATERIAL AND METHOD: In this study, we investigated to what extent the inert ingredients and propellants (freons) influence pulmonary function in 25 asthmatic patients. Forced expiratory volume in one second(FEV,) was measured by spirometry, Autospira HI 498(Chest, Japan) before and 1, 3, 5 and 10 minutes after the inhalation of saline control and MDI-placebo containing freons and inert ingredients. RESULT: Twenty four % (6/25) of asthmatics experienced a decrease in FEV20 by 10% or greater when compared to saline control. Number of positive cases in steroid dependent asthmatics is significantly higher compared to non-steroid dependent asthmatics. (p<0.05) Bronchoconstriction associated with the use of MDI-placebo appeared within 3 to 5 minutes and resolved spontaneouly at 10 minutes after the inhalation. CONCLUSION: The bronchoconstrictive response induced by MDI might be caused by the pro-pellants and/or the other inert ingredients contained in MDIs.

Bronchial hyperrseponsiveness to methacholine in allergic rhinitics sensitized to house dust mites / 천식및알레르기

BACKGROUND: Allergic rhinitis is often associated with bronchial asthma, and intranasal treatment with topical corticosteroids reduces bronchial responsiveness. OBJECTIVE: In this study, it was evaluated that the bronchial responsiveness to methacholine increased in non-asthmatic adults with house dust mites (HDM)-sensitive allergic rhinitis compared to those without, chronic nasal symptoms. SUBJECTS AND METHODS: A questionnaire, skin prick t,est to common inhalant allergens, and methacholine bronchial provocation test (MBPT) were performed in a total of 216 subjects, who were composed of 40 non-asthmatic subjects with HDM-sensitive allergic rhinitis (HAR), 63 HDM-sensitive subjects without nasal symptoms (HS), and 113 non-atopic subjects without nasal symptoms (NHS). The bronchial responsiveness was evaluated by positive rate of MBPT (PC,-methacholine200mg/ml), provocative concentration of methacholine at which FEV, decline to 15% compared to baseline value (PC,-methacholine), and slope of dose-response curve (%fall of FEV, / log[last concentrat,ion of methacholine, mg/ml]). RESULTS: Positive rate of MBPT was significantly increased in HAR than in HS and NHS, and there was no difference between HS and NHS (77.9% vs. 50.7% vs. 38.0%). Log PC[5- methacholine was lower in HAR than in HS and NHS, and lower in HS than in NHS (mean+ SE, 1.568+0.126 vs. 2.05+0.085 vs. 2.277+0.047). Slope of dose-response curve was higher in HAR than in HS and NHS, and there was no difference bet,ween HS and NHS (mean+SE, 22.7 + 11.3 vs. 7.3+ 1.2 vs. 4.9+ 0.5%/mg/ml); CONCLUSION: In non-asthmatic adults with HDM-sensitive allergic rhinitis, the bronchial responsiveness to methacholine increased compared to those without chronic rhinitis.