EXHALED NITRIC OXIDE-1 (NOA-1)
Research Area: Cardiovascular and Respiratory Systems
Expedition(s): 12, 13, 14, 17
Principal Investigator(s): ● Dag Linnarsson, Karolinska Institute, Stockholm, Sweden
RESEARCH OBJECTIVES
Inhaled dust particles can cause inflammation in the
airways of humans on Earth as well as in space. To
study the effects of the inhaled dust particles in space,
investigators examine the amount of the gaseous nitric
oxide, which indicates airway inflammation, exhaled by
crew members. During orbital space flight, and in future
space exploration missions, crew members are exposed
to an increased risk of airway inflammation due to
inhalation of free-floating dust and particles. Analysis of
Fractional Exhaled Nitric Oxide (FENO) is a simple
method to monitor inflamed airway.RESULTS
Results showed that during microgravity, FENO was
significantly lower and fell to nearly half that of preflight
value. In the centrifuge experiments, FENO was
significantly elevated during exposure to 2 and 3 times
the normal gravity. The findings of decreased exhaled
NO in space, increased exhaled, and estimated alveolar
NO values in hypergravity suggested that gravity-
induced changes in alveolar-to-lung capillary gas transfer greatly affect FENO, but there was no
clear trend over time during the stays on the International Space Station or after landing.
According to current models of NO transport, NO originates from conductive airways and alveoli,
each source having a different impact on the exhaled amount. Additionally, NO is taken up by
blood in the alveolar compartment. Thus, a change in FENO may come from an alteration of the
overall balance between production and blood recapture as well as by a change in the airway
production. The principal observation was that exhaled NO is gravity dependent: its values are
lowered in microgravity and elevated in seated humans during hypergravity.
PUBLICATION(S)
Karlsson LL, Kerckx Y, Gustafsson LE, Hemmingsson TE, Linnarsson D. Microgravity decreases
and hypergravity increases exhaled nitric oxide. Journal of Applied Physiology. 2009:1431-1437.
doi: 10.1152/japplphysiol.91081.2008.
This investigation is complete and all results are published.
ESA astronaut Thomas Reiter undertakes
science activities for the Nitric Oxide
Analyzer experiment in 2006. ESA image.