Multiple exercise and histamine challenge in asthmatic patients

Schoeffel, Robin E.; Anderson, Sandra D.; Gillam, I.; Lindsay, D. A.

doi:10.1136/thx.35.3.164

Cited by 80 publications

(25 citation statements)

References 25 publications

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“…One characteristic feature of exercise-induced bronchoconstriction (EIB) is a refractory period during which the repetitive exercise induces less airway obstruction [2,33].…”

Section: Introductionmentioning

confidence: 99%

Influence of exercise-induced bronchoconstriction on refractoriness

Nowak

Jörres

Magnussen

1992

Lung

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This study determined if the degree of exercise-induced refractoriness is determined by the degree of exercise-induced bronchoconstriction. In 12 patients with exercise-induced asthma (mean [SEM] age 27 [3] years) we performed 2 pairs of exercise challenges 45 min apart at different work loads on 2 days. Mean (SEM) total respiratory heat loss during low and high work loads was 3.4 (0.2) and 5.1 (0.4) kcal, respectively. After the first and second exercise challenge at low work loads, mean (SEM) SRaw increased by 107 (15) and 73 (16)% (n.s.), as compared to 361 (40) and 98 (25)% at high work loads (p less than 0.005). We found a correlation between the initial airways response and refractoriness (r = 0.58, p less than 0.005) and conclude that the degree of refractoriness after exercise-induced bronchoconstriction is in part dependent on the severity of exercise-induced bronchoconstriction.

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“…One characteristic feature of exercise-induced bronchoconstriction (EIB) is a refractory period during which the repetitive exercise induces less airway obstruction [2,33].…”

Section: Introductionmentioning

confidence: 99%

Influence of exercise-induced bronchoconstriction on refractoriness

Nowak

Jörres

Magnussen

1992

Lung

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“…To assess the degree of refractoriness the "protection index" was calculated [15], as follows: protection standard % fall -% fall in Ch2 index = × 100 standard % fall A two-way repeated measures analysis of variance (ANOVA) was completed to identify differences in spirometry following the two pretreatment regimens and the two environmental conditions (p<0.05 was taken as the level of significance).…”

Section: Calculations and Data Analysismentioning

confidence: 99%

The effects of indomethacin on refractoriness following exercise both with and without a bronchoconstrictor response

Wilson¹,

Bar‐Or²,

O'Byrne³

1994

Eur Respir J

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T Th he e e ef ff fe ec ct ts s o of f i in nd do om me et th ha ac ci in n o on n r re ef fr ra ac ct to or ri in ne es ss s f fo ol ll lo ow wi in ng g e ex xe er rc ci is se e b bo ot th h w wi it th h a an nd d w wi it th ho ou ut t a a b br ro on nc ch ho oc co on ns st tr ri ic ct to or r r re es sp po on ns se e ABSTRACT: Repeated exercise tests demonstrate refractoriness to the development of exercise-induced asthma (EIA). It is unclear whether it is the initial exercise per se or the resulting bronchoconstriction that causes the attenuated response to the second exercise challenge. This study was designed to determine whether the reported blocking of the refractory period by indomethacin requires a significant bronchoconstriction following the primary exercise challenge.Thirteen asthmatic teenagers (aged 12-16 yrs) were tested on four visits. Each visit included two 7 min treadmill exercise challenges at 80% maximum heart rate, separated by a 30 min rest. Conditions for the second exercise challenge (Ch2) were always thermoneutral (20-22°C and 25-35% relative humidity (RH); whilst challenge one (Ch1) was completed twice in thermoneutral and twice in warm-humid breathing conditions (33-35°C and 90-95% RH). A pretreatment for 3 days in a double-blind design with either placebo or indomethacin was completed. Forced expiratory volume in one second (FEV 1 ) was measured before and repeatedly following each challenge. The % fall in FEV 1 following Ch1 of the placebo thermoneutral trial was taken as reference. "Percent protection" at each visit was expressed as the decrease in EIA following Ch2, compared to reference.Warm-humid breathing reduced the EIA post Ch1 by 75%, whilst providing similar protection to thermoneutral conditions. Indomethacin had no significant effect on EIA after Ch1, but reduced "percent protection" for both warm-humid (from 67 to 16%) and thermoneutral (from 70 to 26%) conditions.The data indicate that inhibitory prostaglandins play a major role in EIA refractoriness and suggest that the release of these prostaglandins is initiated by some exercise factor, independent of the development of bronchoconstriction.

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“…Exercise can reduce bronchial responsiveness to histamine for several hours [20,22]. In our study, a possible effect of the moderate exercise during exposure would be a decrease of bronchial responsiveness to histamine 5 h after exposure.…”

Section: Discussionmentioning

confidence: 97%

Immediate and delayed effects of nitrogen dioxide exposure at an ambient level on bronchial responsiveness to histamine in subjects with asthma

Strand¹,

Salomonsson²,

Lundahl³

et al. 1996

Eur Respir J

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Immediate and delayed effects of nitrogen dioxide exposure at an ambient level on bronchial responsiveness to histamine in subjects with asthma. V. Strand, P. Salomonsson, J. Lundahl, G. Bylin. ERS Journals Ltd 1996. ABSTRACT: The time-kinetics of NO 2 induced effects on bronchial responsiveness are poorly known as most observations have been made shortly after exposure. The aim of this study was to measure nonspecific bronchial responsiveness, lung function and inflammatory markers at different times after NO 2 exposure in asthmatics.Nineteen subjects with mild asthma were exposed to either purified air or 488 µg·m -3 (0.26 ppm) NO 2 for 30 min during intermittent exercise. Airway responsiveness to histamine, specific airway resistance (sRaw) and thoracic gas volume (TGV) were measured 30 min, 5 h, 27 h and 7 days after exposure. Peripheral blood inflammatory mediators and the expression of an adhesion molecule, (Mac-1) on granulocytes, were analysed 30 min and 27 h after exposure.Bronchial responsiveness to histamine was significantly increased 5 h after NO 2 exposure when compared to air (median provocative dose of histamine required to cause 100% increase of sRaw ((PDsRaw,100%) 110 µg after NO 2 exposure vs 203 µg on air). There was a tendency for an increase after 30 min, which was nonsignificant (median PDsRaw,100% 100 vs 153 µg). NO 2 exposure did not affect sRaw, but TGV was significantly reduced after exposure. We found an increased expression of Mac-1 on granulocytes 30 min after NO 2 exposure when compared to pre-exposure values. No effect was seen on tryptase, eosinophil cationic protein (ECP), or myeloperoxidase (MPO).These results suggest that exposure to an ambient level of NO 2 causes a delayed effect on bronchial responsiveness in asthmatics. The increased expression of an adhesion molecule in peripheral blood may indicate a NO 2 -induced priming of human granulocytes.

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Multiple exercise and histamine challenge in asthmatic patients

Cited by 80 publications

References 25 publications

Influence of exercise-induced bronchoconstriction on refractoriness

Influence of exercise-induced bronchoconstriction on refractoriness

The effects of indomethacin on refractoriness following exercise both with and without a bronchoconstrictor response

Immediate and delayed effects of nitrogen dioxide exposure at an ambient level on bronchial responsiveness to histamine in subjects with asthma

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