TY  - JOUR
AU  - Giesbrecht, Gordon G.
A2  - Giesbrecht, Gordon G.
A2  - Younes, Magdy
DB  - BISp
DP  - BISp
KW  - Asthma, belastungsinduziertes
KW  - Atmungssystem
KW  - Kältebelastung
KW  - Pathophysiologie
KW  - Prävention
KW  - Sportmedizin
KW  - Sportpathologie
KW  - Ätiologie
LA  - eng
TI  - Exercise- and cold-induced asthma
TT  - Belastungs- und kaelteinduziertes Asthma
PY  - 1995
N2  - Exercise- and cold-induced asthma are commonly recognized respiratory disorders. The asthmatic response includes several factors contributing to airway narrowing, and thus increased airway resistance. These include airway smooth muscle contraction, mucus accumulation, and bronchial vascular congestion as well as epithelial damage and vascular leakage. The etiology for these disorders is nonantigenic. The primary stimulus is probably a combination of airway cooling and drying (leading to hypertonicity of airway lining fluid). Symptoms generally do not occur during the stimulus period (e.g., exercise) itself. This protection may in part be due to increased catecholamine levels during exercise. The early phase response, which occurs 5 to 15 min poststimulus, may be mediated through a combination of a) direct influences, b) vagal reflexes triggered by airway sensory receptors, or c) responses to mediator release. Spontaneous recovery occurs within 30 min to 2 hrs. There is usually a refractory period of about 1 to 2 hrs during which responses to further stimuli are attenuated. This may be due to depletion of histamine and other mediators. As well, prostaglandin release (mediated via LTD4 which is released during exercise) inhibits further airway narrowing. A late phase response has been reported 4 to 10 hrs poststimulus in some patients. These reactions are accompanied by a second release of histamine and other mediators that cause inflammatory responses and epithelial damage. However, the exercise dependence of this response is debated.      Verf.-Referat
SP  - S. 300-314
SN  - 1066-7814
JO  - Canadian journal of applied physiology
IS  - 3
VL  - 20
M3  - Gedruckte Ressource
ID  - PU199511103729
ER  -