Effect of flight in mission SL-3 on interferon-gamma production by rats

Rats flown in Space Shuttle mission SL-3 were sacrificed after flight and spleens were removed. Cultures of spleen cells were challenged with the mitogen concanavalin-A to attempt to induce interferon-gamma. Most control, ground-based rats had spleen cells that produced moderate titers of interferon-gamma. Spleen cells from flown rats did not produce interferon-gamma in most cases, and one flown rat produced minimally detectable amounts of interferon. These data suggest that interferon-gamma production was inhibited in rats flown in mission SL-3 immediately upon return to earth.