The relevance of kalikrein-kinin system via activation of B2 receptor in LPS-induced fever in rats
| Autor: | Christoph Rummel, Danielle R. Santos, Denis Melo Soares, Glória Emília Petto de Souza, M. C. C. Melo, João B. Calixto, Joachim Roth, Daniela Ott |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty medicine.drug_class FEBRE Bradykinin Endogeny 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound 0302 clinical medicine Icatibant Internal medicine medicine Receptor Pharmacology Kininogen business.industry Captopril Kinin Receptor antagonist 030104 developmental biology Endocrinology chemistry business 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Purpose This study evaluated the involvement of endogenous kallikrein-kinin system and the bradykinin (BK) B 1 and B 2 receptors on LPS- induced fever and the POA cells involved in this response. Material and methods Male Wistar rats received either i.v. (1 mg/kg), i.c.v. (20 nmol) or i.h. (2 nmol) injections of icatibant (B 2 receptor antagonist) 30 or 60 min, respectively, before the stimuli. DALBK (B 1 receptor antagonist) was given either 15min before BK (i.c.v.) or 30 min before LPS (i.v.). Captopril (5 mg/kg, sc.,) was given 1 h prior LPS or BK. Concentrations of BK and total kininogenon CSF, plasma and tissue kallikrein were evaluated. Rectal temperatures (rT) were assessed by telethermometry. Ca ++ signaling in POA cells was performed in rat pup brain tissue microcultures. Results Icatibant reduced LPS fever while, captopril exacerbated that response, an effect abolished by icatibant. Icatibant (i.h.) reduced fever to BK (i.h.) but not that induced by LPS (i.v.). BK increased intracellular calcium concentration in neurons and astrocytes. LPS increased levels of bradykinin, tissue kallikrein and total kininogen. BK (i.c.v.) increased rT and decreased tail skin temperature. Captopril potentiated BK-induced fever an effect abolished by icatibant. DALBK reduced the fever induced by BK. BK (i.c.v.) increased the CSF PGE 2 concentration. Effect abolished by indomethacin (i.p.). Conclusions LPS activates endogenous kalikrein-kinin system leading to production of BK, which by acting on B 2 -receptors of POA cells causes prostaglandin synthesis that in turn produces fever. Thus, a kinin B 2 -receptor antagonist that enters into the brain could constitute a new and interesting strategy to treat fever. |
| Databáze: | OpenAIRE |
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