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Selected contribution: redistribution of pulmonary perfusion during weightlessness and increased gravityTo compare the relative contributions of gravity and vascular structure to the distribution of pulmonary blood flow, we flew with pigs on the National Aeronautics and Space Administration KC-135 aircraft. A series of parabolas created alternating weightlessness and 1.8-G conditions. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood flow during different postural and gravitational conditions. The lungs were subsequently removed, air dried, and sectioned into approximately 2 cm(3) pieces. Flow to each piece was determined for the different conditions. Perfusion heterogeneity did not change significantly during weightlessness compared with normal and increased gravitational forces. Regional blood flow to each lung piece changed little despite alterations in posture and gravitational forces. With the use of multiple stepwise linear regression, the contributions of gravity and vascular structure to regional perfusion were separated. We conclude that both gravity and the geometry of the pulmonary vascular tree influence regional pulmonary blood flow. However, the structure of the vascular tree is the primary determinant of regional perfusion in these animals.
Document ID
20040141426
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Glenny, R. W.
(University of Washington School of Medicine Seattle, Washington 98195, United States)
Lamm, W. J.
Bernard, S. L.
An, D.
Chornuk, M.
Pool, S. L.
Wagner, W. W. Jr
Hlastala, M. P.
Robertson, H. T.
Date Acquired
August 22, 2013
Publication Date
September 1, 2000
Publication Information
Publication: Journal of applied physiology (Bethesda, Md. : 1985)
Volume: 89
Issue: 3
ISSN: 8750-7587
Subject Category
Aerospace Medicine
Distribution Limits
Public
Copyright
Other
Keywords
short duration
Non-NASA Center
Flight Experiment
manned
NASA Discipline Cardiopulmonary
Parabolic Flight

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