Abstract
Animal models are useful for exploring the health consequences of prolonged spaceflight. Capabilities were developed to perform experiments in low earth orbit with on-board sample recovery, thereby avoiding complications caused by return to Earth. For NASA’s Rodent Research-1 mission, female mice (ten 32 wk C57BL/6NTac; ten 16 wk C57BL/6J) were launched on an unmanned vehicle, then resided on the International Space Station for 21/22d or 37d in microgravity. Mice were euthanized on-orbit, livers and spleens dissected, and remaining tissues frozen in situ for later analyses. Mice appeared healthy by daily video health checks and body, adrenal, and spleen weights of 37d-flight (FLT) mice did not differ from ground controls housed in flight hardware (GC), while thymus weights were 35% greater in FLT than GC. Mice exposed to 37d of spaceflight displayed elevated liver mass (33%) and select enzyme activities compared to GC, whereas 21/22d-FLT mice did not. FLT mice appeared more physically active than respective GC while soleus muscle showed expected atrophy. RNA and enzyme activity levels in tissues recovered on-orbit were of acceptable quality. Thus, this system establishes a new capability for conducting long-duration experiments in space, enables sample recovery on-orbit, and avoids triggering standard indices of chronic stress.
Highlights
Previous Russian Cosmos and National Aeronautics and Space Administration (NASA) Space Shuttle missions provided multiple opportunities to perform rodent experiments up to three weeks in duration, which contributed to our current understanding of how mammals adapt to the space environment
The main objective of this work was to develop new capability for conducting long duration, rodent experiments in space which both minimize the complications of non-specific, chronic stress responses and allow for sample recovery on-orbit, thereby avoiding the confounding variables associated with returning to Earth
All animals were healthy throughout the duration of the mission as evidenced by daily video health checks, maintenance of body weights compared with ground controls, and an absence of immune organ atrophy or adrenal hypertrophy relative to ground controls
Summary
Previous Russian Cosmos and NASA Space Shuttle missions provided multiple opportunities to perform rodent experiments up to three weeks in duration, which contributed to our current understanding of how mammals adapt to the space environment. 17,66,67 no sensors for temperature and humidity, metal grid walls, layered 68,69 filter system, interior lighting, crew can access animals on orbit metal grid walls, temperature and humidity sensors, long duration filter for improved odor containment, LED lighting (day), infrared lighting (night), crew can access animals on orbit systems, as well as endocrine, hematologic and metabolic changes[3], results between missions were sometimes inconsistent. The Japanese Space Agency performed important experiments with a newly developed flight hardware system supporting singly-housed mice, which can be centrifuged at 1 g to replace Earth’s gravity level while on the ISS12 Findings from their experiments reveal that 1 g artificial gravity mitigates the expected bone loss and muscle atrophy[12] as well as retinal changes[13] that occur after long duration microgravity. Each of the various flight hardware systems developed for long duration spaceflight has unique features, which have the potential to influence results obtained (Table 1)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
