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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

A key role for Na+/K+-ATPase in the endothelium-dependent oscillatory activity of mouse small mesenteric arteries

Texto completo
Autor(es):
Giachini, F. R. C. [1, 2] ; Carneiro, F. S. [1, 2] ; Lima, V. V. [1, 2] ; Carneiro, Z. N. [1] ; Brands, M. W. [1] ; Webb, R. C. [1] ; Tostes, R. C. [1, 2]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Med Coll Georgia, Dept Physiol, Augusta, GA 30912 - USA
[2] Univ Sao Paulo, Fac Med, Dept Farmacol, Sao Paulo - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Brazilian Journal of Medical and Biological Research; v. 42, n. 11, p. 1058-1067, NOV 2009.
Citações Web of Science: 5
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 mu M) or indomethacin (10 mu M), 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 mu M, an Na(+)/K(+)-ATPase inhibitor), but not K(+) channel antagonists {[}tetraethylammonium (100 mu M, a nonselective K(+) channel blocker), Tram-34 (10 mu M, blocker of intermediate conductance K(+) channels) or UCL-1684 (0.1 mu M, a small conductance K(+) channel blocker)], inhibited the oscillatory activity. The contractile activity was also abolished when experiments were performed at 20 degrees 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 alpha-1 and alpha-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. (AU)

Processo FAPESP: 06/01773-0 - Sistema de sinalização RhoA/Rho-cinase no músculo liso vascular de camundongos com hipertensão induzida por angiotensina II: interação com espécies reativas de oxigênio, interleucina-6 (IL-6) e via de sinalização JAK/STAT
Beneficiário:Rita de Cassia Aleixo Tostes Passaglia
Linha de fomento: Bolsas no Exterior - Novas Fronteiras