NASA News....Possible end to zero gravity bone loss?

RMallon · #1 (**permalink**) 02-November-2001, 07:55 PM

Interesting bit of research going on....

http://science.nasa.gov/headlines/y2...htm?list482392

"A new treatment under study by NASA-funded doctors could reverse bone loss experienced by astronauts in space."

Hypatia · #2 (**permalink**) 20-November-2001, 11:40 AM

I just attended a talk by 2 Russian cosmonauts who spoke on using the lessons from MIR that can be used to get to Mars.
They said that after 6 months on MIR, their cosmonauts lost 50% of their (red, I assume) corpuscles, due to radiation.
Has anyone seen this discussed anywhere; or know where I can get more info?
Since MIR was in a low-Earth orbit; this makes travel through space for 2 years highly risky

ToSeek · #3 (**permalink**) 20-November-2001, 12:18 PM

Quote:

On 2001-11-20 07:40, Hypatia wrote:
Has anyone seen this discussed anywhere; or know where I can get more info?

The loss of red blood cells seems to be attributed more to the microgravity environment than to radiation:

Quote:

Decreases in red blood cell mass and plasma volume have been consistently observed in astronauts after space flight. The losses represent about 5 to 20 percent of the preflight blood volume. This reduction in blood volume has a negative impact when astronauts return to Earth, as it often contributes to impairment of cardiovascular function resulting in orthostatic intolerance. Red blood cell metabolism has also shown consistent changes after long flights. These changes generally take the form of shifts in energy generation (glycolysis).

Another factor influencing hematology is the absence of gravity during space flight, which leads to changes in fluid distribution (body fluids move from the lower body to the upper body). The headward fluid shift occurs in the first hours of a space mission resulting in a negative water balance and reduced plasma volume. Reduced plasma volume increases red blood cell concentration which causes a compensatory decrease in red blood cell mass. Therefore, space flight leads to the development of what is now called "astronaut anemia." Recent studies indicate that the decrease in red blood cell mass is achieved by destroying newly formed red blood cells just before or just after they are released from the bone marrow into the bloodstream. This mechanism for controlling red blood cell mass was first recognized as a result of experiments performed on the Spacelab Life Sciences 1 and 2 missions.
...
How these changes progress with flight duration is not well researched.

from

http://lsda.jsc.nasa.gov/scripts/cf/...erm=Hematology

I did a google.com search on "loss red blood cells space" and came up with several promising links in addition to the one given.

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