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Pulmonary function in microgravityWe report the successful collection of a large quantity of human resting pulmonary function data on the SLS-1 mission. Preliminary analysis suggests that cardiac stroke volumes are high on orbit, and that an adaptive reduction takes at least several days, and in fact may still be in progress after 9 days on orbit. It also suggests that pulmonary capillary blood volumes are high, and remain high on orbit, but that the pulmonary interstitium is not significantly impacted. The data further suggest that the known large gravitational gradients of lung function have only a modest influence on single breath tests such as the SBN washout. They account for only approximately 25% of the phase III slope of nitrogen, on vital capacity SBN washouts. These gradients are only a moderate source of the cardiogenic oscillations seen in argon (bolus gas) and nitrogen (resident gas), on such tests. They may have a greater role in generating the normal CO2 oscillations, as here the phase relationship to argon and nitrogen reverses in microgravity, at least at mid exhalation in those subjects studied to date. Microgravity may become a useful tool in establishing the nature of the non-gravitational mechanisms that can now be seen to play such a large part in the generation of intra-breath gradients and oscillations of expired gas concentration. Analysis of microgravity multibreath nitrogen washouts, single breath washouts from more physiological pre-inspiratory volumes, both using our existing SLS-1 data, and data from the upcoming D-2 and SLS-2 missions, should be very fruitful in this regard.(ABSTRACT TRUNCATED AT 250 WORDS).
Document ID
Document Type
Reprint (Version printed in journal)
Guy, H. J. (University of California San Diego, La Jolla 92093-0931)
Prisk, G. K.
West, J. B.
Date Acquired
August 22, 2013
Publication Date
February 1, 1992
Publication Information
Publication: The Physiologist
Volume: 35
Issue: 1 Suppl
ISSN: 0031-9376
Subject Category
Life Sciences (General)
Distribution Limits
short duration
Non-NASA Center
NASA Discipline Cardiopulmonary
Flight Experiment
NASA Experiment Number 178198 1/2
STS-40 Shuttle Project