The effect of a 14-day flight on body fluids in primates

Using isotopes, two Bion 11 monkeys were examined 36 hours after flight. Total body water and all fluid compartments, particularly extracellular and interstitial fluid, were found to diminish. Blood volume and red blood cell mass also decreased. Forty-two days after flight, fluid compartments returned to normal. After the simulated flight, fluid compartments also tended to decrease but in a lesser degree than after real flight.