[Comparative evaluation of stress-induced depression of normal killer activity in old and young animals and its...

The data are presented on the comparative evaluation of a poststress decrease in the activity of normal killer cells, determined in the test of the release of 41Cr from target cells YAC-1 in young and old CBA mice after 6-hour immobilization. The use of mouse leukocyte interferon and poly I . poly C acid has been shown to be highly effective for the restoration of the activity of normal killer cells in young animals after its stress-induced suppression, while in old animals these immunomodulators have proved to be considerably less effective in restoring the activity of natural killer cells at the period following the stress. The probable role of disturbances, affecting the functional properties of the normal killer cell population in old animals, in the mechanism of the poststress decrease of natural cell-mediated immunity is discussed.