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

The effect of IL-1β and TNFα infused into nucleus tractus solitari (NTS), nucleus parabrachialis medialis (NPBmed) and third cerebral ventricle of normotensive rats on blood pressure (BP) and heart rate (HR) was investigated. Microinfusion of IL-1β and TNFα into the third cerebral ventricle and NPBmed of normotensive rats produced a dose-dependent hypotensive and bradycardic response. A similar cardiovascular response was produced by infusion of IL1β into NTS but not by TNFα. When rats were pre-treated with Escherichia coli lipopolisaccharide (LPS), an enhancement of cardiovascular response elicited by IL-1β and TNFα was found. Thus, IL-1β and TNFα produce cardiovascular responses when infused into specific areas of the CNS. This effect is potentiated by LPS and this may explain the alteration in cardiovascular regulation which can be observed in diseases in which an excess of circulating endotoxins and cytokines may occur.