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Updated: Apr 22, 2026
Exploring the Effects of Spaceflight on Mouse Physiology using the Open Access NASA GeneLab Platform
Published on: January 13, 2019
Effects of microgravity on the mouse triceps brachii muscle
Akihiko Ishihara1, Fumiko Nagatomo1, Masahiro Terada2
1Laboratory of Cell Biology and Life Science, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, 606-8501, Japan.
Introduction:
In this study we investigated the effects of microgravity on the fiber properties of the mouse triceps brachii, a forelimb muscle that has no antigravity function.
Methods:
Mice (n = 7) were exposed to microgravity for 13 days on the space shuttle Atlantis (Space Transportation System-135). The fiber cross-sectional area (CSA) and succinate dehydrogenase (SDH) staining intensity of the triceps brachii muscle were compared with those of controls (n = 7). SDH activity in this muscle was also estimated.
Results:
Microgravity did not affect the body weight, muscle weight, or fiber CSA, but there was reduced SDH staining intensity of all types of fibers, irrespective of the muscle region (P < 0.05). Microgravity also reduced muscle SDH activity (P < 0.05).
Conclusions:
Short-term exposure to microgravity induced a decrease in oxidative capacity, but not atrophy, in the triceps brachii muscle of mice.
