Michael Braukus
Headquarters, Washington, D.C.                                            
March 5, 1992
(Phone:  202/453-1549)

Jane Hutchison
Ames Research Center, Mountain View, Calif.
(Phone:  415/604-9000)


RELEASE: 92-30

NASA TO TEST NEW CELL GROWING SYSTEM


   A novel cell culture system for growing bone cells will 
undergo its first test in weightlessness on this month's Space 
Shuttle mission.  The new system will be part of Space Tissue 
Loss-1 (STL), an experiment co-sponsored by NASA and the Walter 
Reed Army Institute of Research, Washington, D.C.

   Dr. Emily Morey-Holton of NASA Ames Research Center, 
Mountain View, Calif., Life Sciences Division and Charlotte 
Cone of the University of California, San Francisco, developed 
the culture technology at Ames.  "This new culture system holds 
great promise for helping us understand what it takes to put 
minerals into bone," Morey-Holton said.

   The objectives of the STL experiment are to study the 
effects of the microgravity environment on the biochemistry and 
functional activity of various tissues including muscle, bone 
and blood cells.  "The Ames cell cultures in the STL experiment 
will investigate how exposure to microgravity changes the size, 
shape and cellular components of bone cells," Cone said.

   In typical bone cultures, osteoblasts (bone-forming cells), 
grow on a flat surface as a 2-dimensional sheet.  They do not 
look like osteoblasts in living bone, which are 3-dimensional.  
In the new system, Morey-Holton and Cone place bone cells onto 
very tiny "beads" (approximately 0.004 inch in diameter) in 
tissue culture dishes, creating a 3-dimensional culture.  Cell 
bridges (connections) between the beads mineralize 
spontaneously in the new system.

                           - more -
                             - 2 -


   Previous studies of bone from animals exposed to 
microgravity for 1 to 3 weeks have shown a decrease in bone 
mineralization, stiffness and the rate at which osteoblasts 
mature.  Such changes can have serious implications for humans 
on long-duration space voyages.  "While this adaptation may be 
perfectly suited to the new, lower gravity environment, there 
may be some real problems when people return to the normal 
gravity of Earth," Morey-Holton said.

   Cone said the new culture system provides "a valuable 
opportunity to study how bone cells mature in culture over 
time, both on Earth and in space."  Post-flight electron 
microscopic analyses of cells from the flight experiment will 
be conducted by Dr. Stephen Doty of the Hospital for Special 
Surgery in New York City.

                            - end -