Linked Life Data

17495121

Source:http://linkedlifedata.com/resource/pubmed/id/17495121

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-8-1
pubmed:abstractText
CO(2) regulation of lung compliance is currently explained by pH- and CO(2)-dependent changes in alveolar surface forces and bronchomotor tone. We hypothesized that in addition to, but independently of, those mechanisms, the parenchyma tissue responds to hypercapnia and hypocapnia by relaxing and contracting, respectively, thereby improving local matching of ventilation (Va) to perfusion (Q). Twenty adult rats were slowly ventilated with modified Krebs solution (rate = 3 min(-1), 37 degrees C, open chest) to produce unperfused living lung preparations free of intra-airway surface forces. The solution was gassed with 21% O(2), balance N(2), and CO(2) varied to produce alveolar hypocapnia (Pco(2) = 26.1 +/- 2.4 mmHg, pH = 7.56 +/- 0.04) or hypercapnia (Pco(2) = 55.0 +/- 2.3 mmHg, pH = 7.23 +/- 0.02). The results show that lung recoil, as indicated from airway pressure measured during a breathhold following a large volume inspiration, is reduced approximately 30% when exposed to hypercapnia vs. hypocapnia (P < 0.0001, paired t-test), but stress relaxation and flow-dependent airway resistance were unaltered. Increasing CO(2) from hypo- to hypercapnic levels caused a substantial, significant decrease in the quasi-static pressure-volume relationship, as measured after inspiration and expiration of several tidal volumes, but hysteresis was unaltered. Furthermore, addition of the glycolytic inhibitor NaF abolished CO(2) effects on lung recoil. The results suggest that lung parenchyma tissue relaxation, arising from active elements in response to increasing alveolar CO(2), is independent of (and apparently in parallel with) passive tissue elements and may actively contribute to Va/Q matching.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
103
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
710-6
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
CO2 relaxes parenchyma in the liquid-filled rat lung.
pubmed:affiliation
Department of Physiology, University of Washington School of Medicine, USA. mjemery@u.washington.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural