Cytokine Levels in Rat Blood and Brain Structures after Administration of Lipopolysaccharide

We compared cytokine profi le of rat serum and brain structures after immune status modulation by LPS (30 μg/kg intraperitoneally). The content of infl ammatory (IL-1α, IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) and anti-infl ammatory (IL-4 and IL-10) cytokines in biological samples of animals was measured on days 1 and 7 after antigenic stimulation. LPS administration reduced the levels of both infl ammatory and anti-infl ammatory cytokines in the peripheral blood of the rats, especially on the 1st day. LPS administration was also accompanied by specifi c changes in cytokine content in the dorsal hippocampus and anterior cingulate cortex. Antigenic stimulation increased the level of anti-infl ammatory cytokines IL-4 and IL-10 in the examined brain tissues, the changes were most pronounced on day 1 after LPS injection. No signifi cant changes in the levels of proinfl ammatory cytokines in the brain tissue of animals were found at the above terms after LPS injection. Thus, peripheral LPS administration to rats shifts the balance between the infl ammatory and anti-infl ammatory cytokines in the CNS structures towards the latter.