Cold-induced bronchoconstriction: role of cutaneous reflexes vs. direct airway effects.
J Appl Physiol (1985)
; 63(2): 659-64, 1987 Aug.
Article
en En
| MEDLINE
| ID: mdl-3654426
ABSTRACT
To determine the relative contributions of direct airway vs. reflex cutaneous thermal receptor stimulation in cold-induced bronchoconstriction, we isolated these two aspects of cold exposure in 10 asthmatics and 13 normal subjects. Ice packs were applied to the skin of the face, chest, thigh, and upper arm in random sequence while serially measuring specific conductance. In this fashion a limited mapping of skin-mediated bronchoconstriction was established. Warm packs were applied to the same areas of control for any potential nonspecific stimulatory effects. Cooling the skin induced bronchoconstriction to a similar degree in both groups; this effect was very small, did not induce symptoms, and was only seen with stimulation of the face. At another time, the subjects performed isocapnic hyperventilation of frigid air to ascertain their response to direct airway cooling. A moderate but significant correlation existed between skin and airway sensitivity; however, the magnitude of the two responses differed markedly. Breathing cold air at rest had no effect on lung function; however, elevating ventilation promptly produced bronchial narrowing. Hence, in a cold environment, the most potent stimulus for the development of airway obstruction in asthmatics derives from a direct airway effect.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Reflejo
/
Fenómenos Fisiológicos Respiratorios
/
Fenómenos Fisiológicos de la Piel
/
Espasmo Bronquial
/
Frío
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Female
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Humans
/
Male
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
1987
Tipo del documento:
Article