CENTRAL IL-1 DIFFERENTIALLY REGULATES PERIPHERAL IL-6 AND TNF SYNTHESIS

Centrally given interleukin (IL)-1 is known to induce a rapid rises in blood IL-6. To extend this and to examine the mechanism by which this occurs, the effects of intracerebroventricular (icv) injection of hum an recombinant IL-1 beta on mRNA expression of IL-6 and tumour necrosi s factor (TNF) in the spleen and liver were examined in rats. Icy inje ction of IL-1 produced a rapid rise of the tissue mRNA levels of IL-6 and TNF in both organs, prior to and/or in parallel with an increase i n their serum levels. Pretreatment with chlorisondamine, a ganglionic blocking agent, inhibited the IL-6 responses, while it had little infl uence on the TNF responses. The results suggest that brain IL-1 induce s peripheral production of IL-6, but not of TNF, through autonomic ner vous system activation.