Central cardiovascular responses induced by interleukin 1 beta and tumor necrosis factor alpha infused into nucleus tractus solitarii, nucleus parabrachialis medialis and third cerebral ventricle of normotensive rats

The effect of IL-1 beta and TNF alpha infused into nucleus tractus solitari (NTS), nucleus parabrachialis medialis (NPBmed) and third cerebral ventric le of normotensive rats on blood pressure (BP) and heart rate (HR) was inve stigated. Microinfusion of IL-1 beta and TNF alpha into the third cerebral ventricle and NPBmed of normotensive rats produced a dose-dependent hypoten sive and bradycardic response. A similar cardiovascular response was produc ed by infusion of IL1 beta into NTS but not by TNF alpha. When rats were pr e-treated with Escherichia coli lipopolisaccharide (LPS), an enhancement of cardiovascular response elicited by IL-1 beta and TNF alpha. was found. Th us, IL-1 beta and TNF alpha produce cardiovascular responses when infused i nto specific areas of the CNS. This effect is potentiated by LPS and this m ay explain the alteration in cardiovascular regulation which can be observe d in diseases in which an excess of circulating endotoxins and cytokines ma y occur. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.