EXHALED NITRIC OXIDE-2 (NOA-2)
Research Area: Cardiovascular and Respiratory Systems
Expedition(s): 12, 13, 17
Principal Investigator(s): ● Dag Linnarsson, Karolinska Institute, Stockholm, Sweden
RESEARCH OBJECTIVES
Decompression sickness (gas bubbles in the bloodstream) is a concern and common occurrence
in scuba divers. It is unknown if astronauts experience the same type of phenomenon from
extravehicular activities (EVA). NOA-2 is designed to compare the amount of nitric oxide that is
exhaled before and after an EVA to determine if the astronauts experience decompression
sickness.
RESULTS
Exhaled nitric oxide was reduced in microgravity (it is
important to know the baseline if exhaled nitric oxide is
used to monitor airway health in future space activities). A
baseline of exhaled nitric oxide in microgravity and reduced
pressure was established. Molecular diffusion played an
important role in nitric oxide turnover; this has implications
for diagnosing and treating airway inflammation. Nitric oxide
turnover with multiple exhalation flows and lung nitric oxide
diffusing capacity were determined. EVA in the US space suit
did not increase exhaled nitric oxide after EVA was
completed (increased exhaled nitric oxide values could mean
presence of venous gas emboli = decompressions sickness).PUBLICATION(S)
Karlsson LL, Blogg SL, Lindholm P, Gennser M, Hemmingsson
TE, Linnarsson D. Venous gas emboli and exhaled nitric oxide
with simulated and actual extravehicular activity. Respiratory
Physiology and Neurobiology. October 2009;169:s59-s62.
doi: 10.1016/j.resp.2009.04.003.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; however additional results are pending publication.
ISS012E24271 – The Planton Unit
and Medical kits in the Zvezda
Service Module. The Platon unit,
Nitric Oxide Analyzer, used in the
European Space Agency Nitric
Oxide 1 experiment, is in the mid-
left of the image. This image was
taken during Expeditions 12/13
Joint Operations.