[Effect of total exogenous hyperthermia on the activity of natural killer cells]

Murine experiments were undertaken to study the impact of acute and chronic exogenous hyperthermia on the functional activity of natural killers. Single hyperthermia of the animals up to 42 degrees C and thermal shock stages were shown to be followed by suppressed activities of natural killer cells. Daily hyperthermia at 43-44 degrees C for 20 min during 3, 5, and 10 days was characterized by the depressed functional activity of natural killers. Hyperthermia for 20 and 30 days revealed no changes in the activity of natural killer cells. It can be assumed that there is a decrease in antitumor responses of the body in acute hyperthermia and in early chronic hyperthermia.