sr140333b and Fever

Zymosan is a fungal cell wall protein-carbohydrate complex that is known to activate inflammatory pathways through the Toll-like receptors and is commonly used to induce fever. Nevertheless, the central mediators that are involved in the zymosan-induced febrile response are only partially known.. The present study evaluated the participation of prostaglandins, substance P, endothelin-1 (ET-1), and endogenous opioids (eOPs) in the zymosan-induced febrile response by using inhibitors and antagonists in male Wistar rats.. Both nonselective (indomethacin) and selective (celecoxib) cyclooxygenase inhibitors reduced the febrile response induced by an intraperitoneal (i.p.) injection of zymosan. Indomethacin also blocked the increase in the prostaglandin E2 levels in the cerebrospinal fluid. An intracerebroventricular injection of the neurokinin-1, ETB, and μ-opioid receptor antagonists also reduced the febrile response induced by the i.p. injected zymosan. Moreover, the μ-opioid receptor antagonist CTAP also reduced the febrile response induced by intra-articular injection of zymosan.. These results demonstrate that prostaglandins, substance P, ET-1, and eOPs are central mediators of the zymosan-induced febrile response.

Topics: Animals; Body Temperature; Celecoxib; Dinoprostone; Fever; Indomethacin; Infusions, Intraventricular; Injections, Intra-Articular; Injections, Intraperitoneal; Male; Oligopeptides; Peptide Fragments; Piperidines; Rats; Somatostatin; Tropanes; Zymosan

Substance P (SP) is involved in fever that is induced by lipopolysaccharide (LPS) but not by interleukin-1β or macrophage inflammatory protein-1α. Intracerebroventricular (i.c.v.) administration of the neurokinin-1 (NK1) receptor antagonist SR140333B in rats reduced fever that was induced by an i.c.v. injection of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), corticotropin-releasing factor (CRF), endothelin-1 (ET-1), and morphine (MOR). Furthermore, an i.c.v. injection of SP induced a febrile response that was inhibited by indomethacin concomitant with an increase in PGE2 levels in cerebrospinal fluid. Lipopolysaccharide and PGE2 caused higher expression and internalization of NK1 receptors in the hypothalamus which were prevented by SR140333B. These data suggest that SP is an important mediator of fever, in which it induces a prostaglandin-dependent response and is released after TNF-α, IL-6, PGE2, CRF, endogenous opioids, and ET-1.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Body Temperature; Corticotropin-Releasing Hormone; Dinoprostone; Fever; Gene Expression Regulation; Hypothalamus; Indomethacin; Interleukin-6; Male; Morphine; Polysaccharides; Pyrogens; Rats; Rats, Wistar; Receptors, Neurokinin-1; Substance P; Time Factors; Tropanes; Tumor Necrosis Factor-alpha

The present study evaluated the involvement of interleukin(IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, interferon(IFN)-γ, prostaglandins of the E2 series, endothelins, substance P and opioids within the central nervous system in polyinosinic:polycytidylic acid (Poly I:C)-induced fever in rats. Poly I:C injection induced a febrile response which was reduced by intracerebroventricular administration of the antibodies against TNF-α, IL-6, or IFN-γ, or by IL-1 or μ receptor antagonists. Intraperitoneal injection of indomethacin or oral administration of celecoxib also reduced Poly I:C-induced fever. Poly I:C increased prostaglandin E2 levels in the cerebrospinal fluid of the animals which was also reduced by indomethacin. The intracerebroventricular injection of ETB or NK1 receptor antagonists did not alter Poly I:C-induced fever. These data suggest the involvement of IL-1β, TNF-α, IL-6, IFN-γ, prostaglandin E2, and opioids but not endothelins and substance P on Poly I:C-induced fever.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies; Body Temperature; Celecoxib; Central Nervous System; Cytokines; Dinoprostone; Endothelin B Receptor Antagonists; Fever; Indomethacin; Interferon Inducers; Male; Oligopeptides; Peptides; Piperidines; Poly I-C; Pyrazoles; Rats; Rats, Wistar; Sulfonamides; Tropanes

Substance P (SP) is a neuropeptide that can modulate inflammatory mediator release through activation of NK(1) receptors (NK(1)R). Some studies have also suggested the involvement of SP in lipopolysaccharide (LPS)-induced fever. However, the precise contribution of this neuropeptide to the pathways activated during fever is unknown. In this study we investigated the effect of a selective NK(1)R antagonist, SR140333B, on the febrile response induced by LPS and cytokines. Our results show that the systemic injection of SR140333B did not modify the fever induced by LPS at a dose that is able to reduce protein extravasation induced by SP in the skin. On the other hand, intracerebroventricular administration of SR140333B significantly reduced the fever induced by peripheral injection of LPS. These data emphasize an important role for SP in the central nervous system during the febrile response to LPS, and are reinforced by the fact that intracerebroventricular injection of SP also induced fever in a dose-dependent manner in captopril-treated rats. Considering that the febrile response can result from the generation of several endogenous pyrogens, among them interleukin (IL)-1β and macrophage inflammatory protein-1α (CCL3/MIP-1α), we also examined the effect of SR140333B on the fever induced by these cytokines which act through prostaglandin-dependent and -independent mechanisms, respectively. Surprisingly, SR140333B did not modify the febrile response to IL-1β or CCL3/MIP-1α. Altogether these data suggest that the central action of SP is essential for LPS-, but not for IL-1β- or CCL3/MIP-1α-induced fever.

Topics: Animals; Body Temperature; Central Nervous System; Chemokine CCL3; Disease Models, Animal; Dose-Response Relationship, Drug; Fever; Injections, Intraventricular; Interleukin-1beta; Lipopolysaccharides; Male; Neurokinin-1 Receptor Antagonists; Rats; Rats, Wistar; Receptors, Neurokinin-1; Time Factors; Tropanes