Abstract
We recently found that arial natriuretic peptide (ANP) inside and outside the blood-brain barrier inhibits the lipopolysaccharide (LPS)-induced fever in rats in vivo. Since ANP inhibits LPS-induced activation of transcription factors and subsequent production of pyrogenic cytokines in macrophages in vitro, it is possible that brain ANP inhibits the activities of the cytokine-producing brain macrophages, microglias, as well. In the present study, we used the primary culture of microglia to investigate whether ANP inhibit LPS-induced microglial activations through its effect on the activation of proinflammatory transcription factors, NF-κB and AP-1. We examined the production of interleukin-1β and nitric oxide and morphological changes of microglia for its activation. We have gotten interesting results, which we will report in the forthcoming "Meeting of the Physiological Society of Japan". [J Physiol Sci. 2006;56 Suppl:S226]
