Investigations with Macaca mulatta of 4-5 yrs. of age with the body mass of 4.5-6.5 kg showed that 10 days of tilting with the head end at .5 degrees reduced body temperature but not levels of interleukine-1beta and interleukine-6 in blood plasma. On the next days after return of animals to cages IL-6 was found to increase sharply in more than 10 times. On subsequent 4 days both IL -1beta and IL-6 were within the normal range.