Author |
Maquigussa, Edgar
![]() ![]() Arnoni, Carine P. ![]() ![]() Cristovam, Priscila C. ![]() ![]() Oliveira, Andrea S. de ![]() ![]() Higa, Elisa M. S. ![]() ![]() Boim, Mirian A. ![]() ![]() |
Institution | Universidade Federal de São Paulo (UNIFESP) |
Abstract | Sepsis causes impaired vascular reactivity, hypotension and acute renal failure. the ability of the Escherichia coli endotoxin (lipopolysaccharide [LPS]) to impair agonist-induced contractility in mesangial cells, which contributes to LPS-induced renal dysfunction, was evaluated. Agonist-induced intracellular calcium ([Ca(2+)]i) mobilization was analyzed using angiotensin II (AngII). the effect of LPS on the levels of the renin-angiotensin system (RAS) components and the roles of vasodilatation-inducing molecules including AT2 receptor (AT2R) and nitric oxide (NO) in the cell reactivity were also evaluated. Confluent human mesangial cells (HMCs) were stimulated with LPS (0111-B4, 100 mu g/mL). AngII-induced [Ca(2+)]i mobilization was measured by fluorometric analysis using Fura-2AM in the absence and presence of an AT2R antagonist (PD123319). the mRNA and protein levels for angiotensinogen, renin, angiotensin-converting enzyme, AT1R and AT2R were analyzed by realtime reverse transcriptase-polymerase chain reaction and Western blot, respectively. NO production was measured by the chemiluminescence method in the culture media after 24, 48 and 72 h of LPS incubation. After 24 h, LPS-stimulated HMCs displayed lower basal [Ca(2+)]i and an impaired response to AngII-induced rise in [Ca(2+)]i. LPS significantly increased AT2R levels, but did not cause significant alterations of RAS components. PD123319 restored both basal and AngII-induced [Ca(2+)]i peak, suggesting an involvement of AT2R in these responses. the expected increase in NO production was significant only after 72 h of LPS incubation and it was unaffected by PD123319. Results showed that LPS reduced the reactivity of HMCs to AngII and suggest that the vasodilatation induced by AT2R is a potential mediator of this response through a pathway independent of NO. |
Keywords |
sepsis
endotoxin mesangial cell intracellular calcium acute renal failure AT2 receptor nitric oxide |
Language | English |
Sponsor |
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundacao Oswaldo Ramos (FOR) Fundo de Auxilio aos Docentes e Alunos (FADA) |
Date | 2010-06-01 |
Published in | Experimental Biology and Medicine. Maywood: Soc Experimental Biology Medicine, v. 235, n. 6, p. 761-767, 2010. |
ISSN | 1535-3702 (Sherpa/Romeo, impact factor) |
Publisher | Soc Experimental Biology Medicine |
Extent | 761-767 |
Origin |
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Access rights | Closed access |
Type | Article |
Web of Science ID | WOS:000278933200012 |
URI | http://repositorio.unifesp.br/handle/11600/32617 |
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