PT  - JOURNAL ARTICLE
AU  - R W Heaton
AU  - A F Henderson
AU  - B J Gray
AU  - J F Costello
TI  - The bronchial response to cold air challenge: evidence for different mechanisms in normal and asthmatic subjects.
AID  - 10.1136/thx.38.7.506
DP  - 1983 Jul 01
TA  - Thorax
PG  - 506--511
VI  - 38
IP  - 7
4099  - http://thorax.bmj.com/content/38/7/506.short
4100  - http://thorax.bmj.com/content/38/7/506.full
SO  - Thorax1983 Jul 01; 38
AB  - We have investigated possible mechanisms of response to airway cooling by studying the effects of sodium cromoglycate and ipratropium bromide on the changes in airways resistance that followed eucapnic hyperventilation with subfreezing air in a group of 12 patients with mild asthma and 10 normal subjects. We have also studied the period of refractoriness to repeated challenge. Maximum bronchoconstriction was not reduced after the second challenge, but in the asthmatics the one-second forced expiratory volume recovered more rapidly after the second challenge. The response in normal subjects was completely abolished by ipratropium bromide (p less than 0.0005) whereas sodium cromoglycate was without effect. In the asthmatics both ipratropium and cromoglycate were effective in attenuating the response (p less than 0.005). These results suggest that in normal subjects the response to airway cooling is produced predominantly via neural mechanisms, whereas in asthmatics there is an additional mechanism which can be abolished by sodium cromoglycate.