Effect of Interleukin-4 on Peripheral Blood Leukocytes in Rats with Various Behavioral Characteristics During Acute Stress

We studied the effect of anti-inflammatory cytokine IL-4 (5 mu g/kg intraperitoneally) on peripheral blood leukocytes in Wistar rats with various behavioral characteristics during acute emotional stress (1-h immobilization with simultaneous subthreshold electrocutaneous stimulation). IL-4 reduced the differences in blood leukocyte count in rats with various behavioral characteristics, which was related to a significant decrease in this parameter in active animals. IL-4 injection to active animals was accompanied by changes in the leukogram (development of neutrophilia, monocytopenia, and lymphopenia) and had a modulatory effect on leukocyte indexes of cell reactivity. Blood leukocyte count in cytokine-treated animals did not change after stress exposure. IL-4 prevented shifts in leukocyte indexes of cell reactivity, which was found after acute stress exposure. Our results expand current notions on the specific involvement of endogenous immunomodulatory compounds in the realization of adaptive and compensatory processes in mammals during negative emotiogenic exposures.