| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
A key role for Na+/K+-ATPase in the endothelium-dependent oscillatory activity of mouse small mesenteric arteries
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| Autores: |
Giachini,F.R.C.
Carneiro,F.S.
Lima,V.V.
Carneiro,Z.N.
Brands,M.W.
Webb,R.C.
Tostes,R.C.
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| Data: |
2009-11-01
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| Ano: |
2009
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| Palavras-chave: |
Oscillatory activity
Na+/K+-ATPase pump
Ouabain
Small mesenteric arteries
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| Resumo: |
Oscillatory contractile activity is an inherent property of blood vessels. Various cellular mechanisms have been proposed to contribute to oscillatory activity. Mouse small mesenteric arteries display a unique low frequency contractile oscillatory activity (1 cycle every 10-12 min) upon phenylephrine stimulation. Our objective was to identify mechanisms involved in this peculiar oscillatory activity. First-order mesenteric arteries were mounted in tissue baths for isometric force measurement. The oscillatory activity was observed only in vessels with endothelium, but it was not blocked by L-NAME (100 µM) or indomethacin (10 µM), ruling out the participation of nitric oxide and prostacyclin, respectively, in this phenomenon. Oscillatory activity was not observed in vessels contracted with K+ (90 mM) or after stimulation with phenylephrine plus 10 mM K+. Ouabain (1 to 10 µM, an Na+/K+-ATPase inhibitor), but not K+ channel antagonists [tetraethylammonium (100 µM, a nonselective K+ channel blocker), Tram-34 (10 µM, blocker of intermediate conductance K+ channels) or UCL-1684 (0.1 µM, a small conductance K+ channel blocker)], inhibited the oscillatory activity. The contractile activity was also abolished when experiments were performed at 20°C or in K+-free medium. Taken together, these results demonstrate that Na+/K+-ATPase is a potential source of these oscillations. The presence of α-1 and α-2 Na+/K+-ATPase isoforms was confirmed in murine mesenteric arteries by Western blot. Chronic infusion of mice with ouabain did not abolish oscillatory contraction, but up-regulated vascular Na+/K+-ATPase expression and increased blood pressure. Together, these observations suggest that the Na+/K+ pump plays a major role in the oscillatory activity of murine small mesenteric arteries.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009001100010
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X2009005000033
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.42 n.11 2009
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| Direitos: |
info:eu-repo/semantics/openAccess
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