Interleukin-1 stimulates the release of dopamine and dihydroxyphenylacetic acid from the hypothalamus in vivo.

Push-pull perfusion technique was used to infuse IL-1 beta into and collect perfusate from the medial basal hypothalamus of freely moving male rats. Dopamine (DA) and its metabolite, dihydroxyphenylacetic acid (DOPAC), were measured in the perfusate using high performance liquid chromatography with electrochemical detection. In the control group, release rates of DA and DOPAC decreased and were 62% and 40%, respectively, below pretreatment levels after 325 min. In contrast, treatment with 50 ng of IL-1 beta produced substantial reductions in these decreases, and treatment with 100 ng of IL-1 beta produced increases of up to 118% and 89% in the release rates of DA and DOPAC, respectively. It is concluded that IL-1 beta affects the metabolism of catecholamines (and probably other neurotransmitters) in the brain, which, in turn, mediate its central and neuroendocrine actions.