Linked Life Data

2122785

Source:http://linkedlifedata.com/resource/pubmed/id/2122785

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1990-12-4
pubmed:abstractText
We studied the effect of changing the duration of isocapnic hyperventilation on the time course of bronchoconstriction in five subjects with asthma. Each subject performed hyperventilation challenges of 4, 8, and 16 min. No significant bronchoconstriction occurred until the hyperventilation was stopped, regardless of its duration. We found increased bronchoconstriction as the duration of hyperventilation increased. The declines in FEV1 (mean +/- SD) from baseline were 13 +/- 10%, 22 +/- 7%, and 29 +/- 12% for 4, 8, and 16 min of hyperventilation, respectively (1 versus 3, p less than 0.01). Mean times after hyperventilation until maximal bronchoconstriction were 12 +/- 4 min, 9 +/- 6 min, and 6 +/- 4 min. We also found slight bronchodilation during the first 4 min of hyperventilation. After 2 and 4 min of hyperventilation, the FEV1 was 103 +/- 5% and 103 +/- 3% of baseline, respectively (both p less than 0.05, compared to baseline). We conclude that increasing the duration of hyperventilation delays the onset of bronchoconstriction but causes greater bronchoconstriction once the hyperventilation is stopped. These results suggest that either hyperventilation itself inhibits bronchoconstriction or that the mechanisms that induce bronchoconstriction in response to hyperventilation operate after, rather than during, hyperventilation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
142
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1133-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
The time course of bronchoconstriction in asthmatics during and after isocapnic hyperventilation.
pubmed:affiliation
University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't