Exogenous IL-1ß induces its own expression, but not that of IL-6 in the hypothalamus and activates HPA Axis and prolactin release
Abstract
Objective: Proinflammatory cytokines IL-1ß, and IL-6 are synthesized in the brain, where they exert local regulatory functions. Our aim was to find out whether, along with the activation of hypothalamo-pituitary-adrenocortical (HPA) axis and prolactin (PRL), the acute systemic enhancement of IL-1ß affects its own production in the hypothalamus as well as that of IL-6.
Method: Forty five minutes after a single i.p. administration of recombinant rat IL-1ß (5 μg/ kg) to male Long Evans rats we estimated the expression of IL-1ß and IL-6 mRNA in the hypothalamus by real time PCR, ACTH, corticosterone (CORT), and PRL by RIA Results: IL-1ß administration stimulated the expression of IL-1ß mRNA in the hypothalamus by 99 %, but not that of IL-6. It also significantly activated plasma levels of ACTH, PRL, CORT, and CORT production in adrenal gland.
Conclusion: These results indicate that acute peripheral enhancement of IL-1ß may induce neuroendocrine changes also via the immediate activation of its own expression in the hypothalamus, but not that of IL-6 expression in the hypothalamus was found.