[Effect of a 49-day space flight on immunological reactivity indices and on the blood protein makeup in the crew of Saliut-5].

The prolonged 49-day space flight resulted in a significant inhibition of immunological reactivity of the Salyut-5 crewmembers which involved a decline in bactericidal activity of the serum and lysozyme activity of the saliva, and a decrease in the content of immunoglobulins in the saliva and tonsillary lacunae. After the flight recovery of reduced immunoreactivity took a longer time than after shorter-term flights. The prolonged space mission led to an increase of most globulin fractions and a decrease of albumin in blood. With respect to globulin fractions, a predominant increase in the content of C3c and C4-factors of the complement and immunoglobulins G, A, M was noted. Blood proteins returned to normal within a long period of time.