Systemic administration of interleukin-1 stimulates norepinephrine release in the paraventricular nucleus

The purpose of this study was to investigate the effects of circulating interleukin-1 beta (IL-1 beta) on the release of norepinephrine (NE) in the paraventricular nucleus (PVN). After intraperitoneal administration of IL-1 beta, NE was measured by high performance liquid chromatography in the perfusate collected from the PVN of conscious, freely moving rats by the technique of push-pull perfusion. IL-1 beta produced an increase in NE release. Both the strength and duration of NE release were dose-dependent. It is concluded that circulating IL-1 beta activates the noradrenergic innervation to the PVN and that this is part of the mechanism by which it stimulates the release of the corticotropin-releasing hormone (CRH) and produces its other neuroendocrine and central effects.