Biomaterial Database

Exercise refractoriness after histamine inhalation in asthmatic subjects. 1988

C M Hamielec, and P J Manning, and P M O'Byrne

Department of Medicine, McMaster University, Hamilton, Ontario, Canada.

Both exercise and histamine inhalation cause bronchoconstriction in asthmatic subjects. Repeated challenges with both stimuli cause less bronchoconstriction. Exercise refractoriness and histamine tachyphylaxis may occur through release of inhibitory mediators in the airways. The purpose of this study was to determine whether prior challenge with exercise or histamine reduced the subsequent bronchoconstriction to the opposite challenge. Eight asthmatic subjects with exercise bronchoconstriction were studied on 4 study days. On each study day, two consecutive tests were separated by 1 h as follows: on Day 1, two exercise challenges; on Day 2, two histamine inhalation tests; on Days 3 and 4, a histamine test was followed by an exercise challenge or an exercise challenge was followed by a histamine test. On Day 1, the mean fall in the FEV1 after the initial exercise challenge was 22.13% (SD, 7.12%); after the second exercise challenge, 1 h later, it was 11.13% (SD, 10.69%) (p less than 0.005). On Day 2, the provocative concentration of histamine causing a 20% fall in FEV1 (PC20) was 1.68 mg/ml (%SD, 2.02) for the first test and 2.68 mg/ml (%SD, 1.99) for the second test 1 h later (p less than 0.005). However, after exercise bronchoconstriction, the histamine PC20 was 1.88 mg/ml (%SD, 2.03), not different from the control value (p less than 0.5). In contrast, the fall in FEV1 after exercise after prior inhalation of histamine was 15.63% (SD, 10.0%) compared with 23.13% (SD, 8.6%) on the control day (p less than 0.005). Therefore, inhibitory mediators released during histamine inhalation can cause exercise refractoriness; however, the converse is not true.

UI	MeSH Term	Description	Entries
D001986	Bronchial Spasm	Spasmodic contraction of the smooth muscle of the bronchi.	Bronchospasm,Bronchial Spasms,Bronchospasms,Spasm, Bronchial,Spasms, Bronchial
D005541	Forced Expiratory Volume	Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.	Forced Vital Capacity, Timed,Timed Vital Capacity,Vital Capacity, Timed,FEVt,Capacities, Timed Vital,Capacity, Timed Vital,Expiratory Volume, Forced,Expiratory Volumes, Forced,Forced Expiratory Volumes,Timed Vital Capacities,Vital Capacities, Timed,Volume, Forced Expiratory,Volumes, Forced Expiratory
D006632	Histamine	An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.	Ceplene,Histamine Dihydrochloride,Histamine Hydrochloride,Peremin
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000280	Administration, Inhalation	The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.	Drug Administration, Inhalation,Drug Administration, Respiratory,Drug Aerosol Therapy,Inhalation Drug Administration,Inhalation of Drugs,Respiratory Drug Administration,Aerosol Drug Therapy,Aerosol Therapy, Drug,Drug Therapy, Aerosol,Inhalation Administration,Administration, Inhalation Drug,Administration, Respiratory Drug,Therapy, Aerosol Drug,Therapy, Drug Aerosol
D001249	Asthma	A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).	Asthma, Bronchial,Bronchial Asthma,Asthmas
D015444	Exercise	Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.	Aerobic Exercise,Exercise, Aerobic,Exercise, Isometric,Exercise, Physical,Isometric Exercise,Physical Activity,Acute Exercise,Exercise Training,Activities, Physical,Activity, Physical,Acute Exercises,Aerobic Exercises,Exercise Trainings,Exercise, Acute,Exercises,Exercises, Acute,Exercises, Aerobic,Exercises, Isometric,Exercises, Physical,Isometric Exercises,Physical Activities,Physical Exercise,Physical Exercises,Training, Exercise,Trainings, Exercise