Differential induction of functional B1-bradykinin receptors along the rat nephron in endotoxin induced inflammation

Differential induction of functional B1-bradykinin receptors along the rat nephron in endotoxin induced inflammation

Autor Marin-Castano, M. E. Google Scholar
Schanstra, J. P. Google Scholar
Praddaude, F. Google Scholar
Pesquero, João Bosco Autor UNIFESP Google Scholar
Ader, J. L. Google Scholar
Girolami, J. P. Google Scholar
Bascands, J. L. Google Scholar
Instituição Inst Louis Bugnard
Universidade Federal de São Paulo (UNIFESP)
Resumo Background, Under physiological conditions, the effects of kinins in the kidney are mainly mediated by the bradykinin B2-receptor, whereas the kinin B1-receptor is strongly induced under inflammatory conditions in a variety of tissues. Knowledge of the distribution of the B1-receptor along the nephron is of importance since the B1-receptor might replace B2-receptors under these conditions.Methods. Using a RT-PCR/Southern blot approach allowing relative quantification of mRNA levels, ten different microdissected rat nephron segments were analyzed for the presence of the B1- and B2-receptor before and after endotoxin treatment to induce experimental inflammation, the functionality of the expressed receptors was assessed by kinin-induced intracellular calcium ([Ca2+](i)) mobilization in microdissected nephron segments.Results. While under physiological conditions no B1-receptor mRNA could be detected, after 18 hours of treatment with bacterial lipopolysaccharide (LPS) the expression of B1-receptor mRNA was strongly induced in the efferent arteriole, the medullary and inner medullary thin limb, and in the distal tubule. Moderate expression was found in the glomerulus, proximal convoluted and straight tubules, and in the medullary thick ascending limb. Small but detectable expression was observed in the cortical collecting duct. the induction of BI-receptor mRNA expression resulted in functional receptor expression, since increases in [Ca2+](i) were observed upon B1-agonist stimulation. LPS treatment also increased the expression of B2-receptor mRNA in all nephron segments except in the glomerulus, the inner medullary thin limb and the outer medullary collecting duct. However, no related changes in B2-agonist induced rises in [Ca2+](i) were found.Conclusions. These studies show a functional induction of the B1-kinin receptor along the rat nephron, which should be taken in account to address the effects of kinins under inflammatory conditions in the kidney.
Palavra-chave des-Arg(9)bradykinin
kinin-receptors
inducible gene expression
nephron
microdissection
Idioma Inglês
Data de publicação 1998-12-01
Publicado em Kidney International. Malden: Blackwell Science Inc, v. 54, n. 6, p. 1888-1898, 1998.
ISSN 0085-2538 (Sherpa/Romeo, fator de impacto)
Publicador Blackwell Science Inc
Extensão 1888-1898
Fonte http://dx.doi.org/10.1046/j.1523-1755.1998.00201.x
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:000077129000009
Endereço permanente http://repositorio.unifesp.br/handle/11600/25983

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