Wintering grizzly bears are the key to preventing muscle from flushing away in humans
Wintering grizzly bears can shed light on how muscle wasting of astronauts in microgravity and life support patients can be reduced
- People who don’t use their muscles often see their muscles wasting quickly
- This includes bedridden patients and astronauts who are in space
- But grizzly bears can overwinter for six months and maintain muscle size and tone
- Scientists now hope to see if they can deprive the secrets of the genes of the grizzly bear and use it as a therapy for humans
Wintering grizzly bears can be the key to preventing muscle wasting in humans, offering new hope to bedridden patients and astronauts in space.
People, like all animals that stay awake all year round, see their muscles entering atrophy – a waste process that reduces tissue – if it is not used for a long time.
This is particularly a problem for intensive care patients who breathe through a ventilator because the membrane starts wasting away within a few hours.
But wintering animals, including the common grizzly bear, can slumber for a few months in the winter and still retain their muscle size and tone.
Scientists have begun to unravel the secrets behind this phenomenon and have found a handful of genes and processes that can help prevent muscle atrophy.
They now hope to turn their findings into medicines to help people susceptible to atrophy.
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But wintering animals, including the mean grizzly bear, lay in rest for several winter months and retain their muscle size and tone. The secret of this could be in their genes because cells produce non-essential amino acids that stimulate cell growth to maintain muscle
WHAT IS HIBERNATION?
Sleeping is a mechanism used by many animals to help them survive cold weather.
During the winter months the temperature drops, food is scarce and survival can be difficult.
Hibernation is different depending on the species, but they all wake up in the spring when the temperatures recover.
The metabolism of hibernation slows and the temperature drops, this helps to save energy and resources.
Breathing also slows down and in some animals, also the heartbeat.
Some cold-blooded animals, such as wood frogs, produce natural antifreeze to survive when frozen.
mammals that go into hibernation must store a large amount of fat by eating considerably during the weeks that are approaching sleep,
This layer of extra fat allows them to survive sleep – insufficient fat reserves can lead to hunger during sleep.
People who are unable to activate and use their muscles for a long time quickly contract atrophy, including astronauts in space.
In space, for example on the ISS, the lack of gravity means that muscles hardly need to work and astronauts have a powerful training routine to prevent them from losing large amounts of muscle mass.
It is a major obstacle to future space exploration missions, including planned manned missions to Mars.
But grizzly bears, a large mammal hibernating for about six months, come out of its long-term sleep without noticeable loss of muscle size.
Scientists have long searched for the reasons behind this remarkable preservation and academics at the Max Delbruck Center for Molecular Medicine in Berlin published a paper in the journal Scientific reports investigate the phenomenon.
‘Muscle atrophy is a real human problem that occurs in many circumstances. We are still not very good at preventing it, “says the lead author of the study, Dr. Douaa Mugahid.
Muscle samples were taken from four bears in captivity of researchers at Washington State University and assessed.
Researchers were specifically looking for signs of increased activity in muscle cell genes that produce proteins.
Proteins are the key to maintaining muscle growth and recovery and their building blocks, amino acids, are considered the key to the process.
In space, for example on the ISS, the lack of gravity means that muscles hardly need to work and astronauts have a powerful training routine to prevent them from losing large amounts of muscle mass (file)
The study showed that some proteins in the muscles change how a bear processes these amino acids during hibernation.
They change the metabolism of the grizzly and this causes the muscle cells to contain larger amounts of certain non-essential amino acids (NEAAs).
Researchers believe that these NEAAs may be the key to stopping atrophy over time, but it has already been proven that they are taken as pills.
The muscle must be forced to produce it itself to ensure that the NEAAs reach the right place and can work properly.
This research area has not been fully tested and scientists are now hoping to find out if certain paths can be activated to start the process.
A handful of promising genes were discovered and are now being examined to see if they have therapeutic potential.
“We will now investigate the effects of deactivating these genes,” says Michael Gotthardt, who led the research.
“After all, they are only suitable as therapeutic targets if there are limited or no side effects.”
WHY TRAIN ASTRONAUTS IN SPACE, AND WHAT DO IT DO?
Body fluids are moved with micro gravity. Liquids such as plasma are lost throughout the body. Plasma is where red blood cells live.
Less plasma means that there is less blood to transport oxygen to the rest of the body.
However, exercise has shown that it increases the amount of plasma in the body. Astronauts who exercise make more red blood cells.
Micro gravity also brings about a change in something called orthostatic intolerance.
If you get up quickly and feel light in your head, that is orthostatic intolerance.
Your body tries to prevent this. It does this by raising the heart rate and blood pressure to return more blood to your heart.
If you can’t do that, you’ll faint. Without gravity and less blood volume, astronauts are more susceptible to fainting.
Again, exercise can help increase blood volume and circulation. That helps prevent fainting.
Astronauts must exercise in the room for two hours a day to prevent bone and muscle loss.
Weakened astronauts would be less able to perform tasks in space. If an emergency occurs, they must also be in good condition to get out of a spacecraft or station quickly.
Once they land on Earth, weakened muscles and bones would make walking difficult.
Muscle can be built with therapy. But lost bone is not that easy to come back.
Three main exercises in the room:
Astronauts use three training equipment.
- Cycle ergometer: this looks like a bicycle and the most important activity is pedaling. It is used to measure fitness in the room because it is easy to monitor the heart rate and how much work is being done.
- Treadmill: walking or jogging on the treadmill is like walking on earth. Running is the most important way to keep your bones and muscles healthy. Because the lack of gravity tends to make people float, harnesses are attached to the astronauts to keep them on the tread.
- Resistance Exercise Device (RED): The RED looks like weight lifting machines that you can see on television. To use it, astronauts pull and turn elastic rubber band-like cords attached to pulleys. The RED can be used for total body training. From squats and bending exercises for the legs, to arm exercises and heel lifts, astronauts can do them all on RED. Russians and Americans have different exercise routines on the space station. But they all have the same goal: to keep the astronauts and cosmonauts healthy.