Heterogeneity of glomerular perfusion and filtration induced by epinephrine and norepinephrine

Heterogeneity of glomerular perfusion and filtration induced by epinephrine and norepinephrine

Autor Boim, Mirian Aparecida Autor UNIFESP Google Scholar
Stella, Sergio R. Autor UNIFESP Google Scholar
Pereira, A.b. Autor UNIFESP Google Scholar
Schor, Nestor Autor UNIFESP Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo The role of catecholamines in the distribution of intrarenal blood flow and in single-nephron glomerular filtration rate (SNGFR) was evaluated in anesthetized Wistar rats by the Hanssen technique. Epinephrine (EPI) and norepinephrine (NOR) were infused to produce elevations of 20-30 mmHg in mean arterial pressure. Superficial and juxtamedullary nephron perfusion and filtration were determined by the presence of Prussian blue dye. In the control group, 100% of the nephrons presented a homogeneous pattern of perfusion and filtration. In contrast, a heterogeneous distribution of the dye was found even in the larger arteries (arciform and radial), indicating variable perfusion and filtration in both superficial and juxtamedullary nephrons. The effects of EPI and NOR were also evaluated in the superficial cortex by the micropuncture technique in two additional groups of Munich-Wistar rats. Mean SNGFR was 27% and 54% lower in the EPI- and NOR-treated groups, respectively. No change in mean intraglomerular hydraulic pressure was observed after EPI or NOR infusion in spite of a highly scattered pattern, indicating an important variability in perfusion along the superficial cortex, and/or different sensitivity of the pre- and post-glomerular arterioles. The present data suggest that EPI and NOR may affect intrarenal hemodynamics by modifying perfusion and filtration in both superficial and juxtamedullary glomeruli and not by shifting blood flow from superficial to juxtamedullary nephrons. The heterogeneous pattern of perfusion was a consequence of differential vasoconstriction along the intrarenal arteries, probably due to different density and/or sensitivity of the adrenergic receptor subtypes present in the intrarenal vascular tree.
Palavra-chave catecholamines
intrarenal blood flow
glomerular function
Hanssen technique
micropuncture
Idioma Inglês
Data de publicação 1997-08-01
Publicado em Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 30, n. 8, p. 1023-1031, 1997.
ISSN 0100-879X (Sherpa/Romeo, fator de impacto)
Publicador Associação Brasileira de Divulgação Científica
Extensão 1023-1031
Fonte http://dx.doi.org/10.1590/S0100-879X1997000800017
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:A1997XT03600017
SciELO S0100-879X1997000800017 (estatísticas na SciELO)
Endereço permanente http://repositorio.unifesp.br/handle/11600/505

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