Experiments Show Artificial Gravity Can Prevent Muscle Loss in Space

FYI,

"Experiments Show 'Artificial Gravity' Can Prevent Muscle Loss in
Space"
http://www.spaceref.com/news/viewpr.rss.spacewire.html?pid(795
University of Texas Medical Branch at Galveston Press Release

: UTMB / NASA study used centrifuge and simulated weightlessness with
: bed rest

: When the Apollo 11 crew got back from the moon 40 years ago this
: week, they showed no ill effects from seven days spent in
: weightlessness. But as American astronauts and Soviet cosmonauts
: began conducting longer-duration space flights, scientists noticed
: a disturbing trend: the longer humans stay in zero gravity, the
: more muscle they lose. Space travelers exposed to weightlessness
: for a year or more -- such as those on a mission to Mars, for
: example -- could wind up crippled on their return to Earth, unable
: to walk or even sit up.

: Now, researchers at the University of Texas Medical Branch at
: Galveston have conducted the first human experiments using a device
: intended to counteract this effect -- a NASA centrifuge that spins
: a test subject with his or her feet outward 30 times a minute,
: creating an effect similar to standing against a force two and half
: times that of gravity. Working with volunteers kept in bed for
: three weeks to simulate zero-gravity conditions, they found that
: just one hour a day on the centrifuge was sufficient to restore
: muscle synthesis.

: "This gives us a potential countermeasure that we might be able to
: use on extended space flights and solve a lot of the problems with
: muscle wasting," said UTMB associate professor Douglas Paddon-Jones,
: senior author of a paper on the centrifuge research in the July
: issue of the Journal of Applied Physiology. "This small amount of
: loading, one hour a day of essentially standing up, maintained the
: potential for muscle growth."

: Fifteen healthy male volunteers participated in the study, carried
: out in UTMB's General Clinical Research Center. All spent 21 days
: lying in a slightly head-down position that previous investigations
: have shown produces effects on muscles like those of
: weightlessness. Eight rode the centrifuge daily. Measurements of
: protein synthesis and breakdown in thigh and calf muscle were taken
: at the beginning and end of the investigation, using muscle
: biopsies and blood samples. The results showed that members of the
: centrifuge group continued to make thigh muscle protein at a normal
: rate, while the control group's muscle synthesis rate dropped by
: almost half.

: Paddon-Jones cautioned that the rate of muscle protein synthesis
: alone does not necessarily predict changes in muscle function. But,
: he pointed out, it was still a strong indicator that a relatively
: brief intervention could have a positive effect in preventing
: zero-gravity muscle loss -- one that might also be applied on Earth.

: "We've studied elderly inpatients here at UTMB -- 95 percent of the
: time they're completely inactive, and in three days they lose more
: than a kilogram of muscle," Paddon-Jones said. "A human centrifuge
: may not be the answer, but we are interested in seeing if something
: as simple as increasing the amount of time our patients spend
: standing and moving can slow down this process. This NASA research
: is one of a series of important studies that we hope to ultimately
: translate to a clinical population."

: The other authors of the Journal of Applied Physiology article
: ("Artificial gravity maintains skeletal muscle protein synthesis
: during 21 days simulated microgravity") were assistant professor
: T. Brock Symons, associate professor Melinda Sheffield-Moore,
: associate professor David L. Chinkes and professor Arny Ferrando.
: NASA, the National Institutes of Health and UTMB's Claude D. Pepper
: Older Americans Independence Center provided support for the
: investigation.

Mark Reiff