Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-5-16
pubmed:abstractText
We hypothesized that the perfusion heterogeneity in the human, upright lung is determined by nongravitational more than gravitational factors. Twelve and six subjects were studied during two series of parabolic flights. We used cardiogenic oscillations of O(2)/SF(6) as an indirect estimate of intraregional perfusion heterogeneity (series 1) and phase IV amplitude (P(4)) as a indirect estimate of interregional perfusion heterogeneity (series 2). A rebreathing-breath holding-expiration maneuver was performed. In flight, breath holding and expiration were performed either in microgravity (0 G) or in hypergravity. Controls were performed at normal gravity (1 G). In series 1, expiration was performed at 0 G. Cardiogenic oscillations of O(2)/SF(6) were 19% lower when breath holding was performed at 0 G than when breath holding was performed at 1 G [means (SD): 1.7 (0.3) and 2.3 (0.6)% units] (P = 0.044). When breath holding was performed at 1.8 G, values did not differ from 1-G control [2.6 (0.8)% units, P = 0.15], but they were 17% larger at 1.8 G than at 1 G. In series 2, expiration was performed at 1.7 G. P(4) changed with gravity (P < 0.001). When breath holding was performed at 0 G, P(4) values were 45 (46)% of control. When breath holding was performed at 1.7 G, P(4) values were 183 (101)% of control. We conclude that more than one-half of indexes of perfusion heterogeneity at 1 G are caused by nongravitational mechanisms.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2268-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Residual heterogeneity of intra- and interregional pulmonary perfusion in short-term microgravity.
pubmed:affiliation
Dept. of Physiology and Pharmacology, Section of Environmental Physiology, Karolinska Institutet, Berzelius väg 13, SE-171 77 Stockholm, Sweden. stephanie.montmerle@fyfa.ki.se
pubmed:publicationType
Journal Article, Clinical Trial, Controlled Clinical Trial, Research Support, Non-U.S. Gov't