Mutant mice sent to the International Space Station (ISS) on a SpaceX rocket returned to Earth maintaining their significant muscle mass thanks to an experimental drug, scientists have revealed.
The research offers hope for astronauts who usually lose a significant amount of bone and muscle mass while in zero-gravity environments, as well as people on Earth confined to beds or wheelchairs.
Scientists sent 40 young female black mice to the ISS last December, where they were tended to by astronauts Jessica Meir and Christina Koch in an experiment with a novel treatment designed to prevent muscle and bone loss.
Astronauts Jessica Meir (L) and Christina Koch looked after the mice
The regular mice sent into space lost up to 18% of their mass due to the zero-gravity environment, according to the paper published in the Proceedings of the National Academy of Sciences.
But eight genetically engineered “mighty mice”, with double the muscle of their fellows, managed to maintain their mass at a level comparable to mice which remained on Earth at NASA’s Kennedy Space Centre.
Even more startlingly, eight other normal mice that were not genetically engineered, but that were given doses of the “mighty mouse” drug, returned to Earth with dramatically bigger muscles.
Some of the ordinary mice that returned from the ISS in January were then injected with the drug after being brought back to the Kennedy Space Centre – and again quickly developed more muscle than mice which went untreated.
The drug blocks a pair of receptors for myostatin and activin proteins, which typically limit skeletal muscle mass development, according to phys.org, which reported on the study.
A ‘twice-muscled’ mouse and a normal one. Pic: Dr Se-Jin Lee
Dr Se-Jin Lee, who led the research from the Jackson Laboratory in Connecticut, said there was “an embarrassment of riches” to be found in similar studies.
His wife, Dr Emily Germain-Lee, who also took part in the study, said that more work was needed before the drug could be tested on humans without potentially dangerous side effects.
“We’re years away, but that’s how everything is when you go from mouse to human studies,” Dr Germain-Lee added.