Altered Vascular Response to the K+induced Vasorelaxation in Aortic Smooth Muscle of Renal Hypertensive Rats
Korean Circulation Journal
;
: 980-988, 2000.
Artigo
em Coreano
| WPRIM
| ID: wpr-144595
ABSTRACT
BACKGROUND:
An increase of the extracellular K+concentrations up to about 8 mM in the isolated vessels causes relaxation in pre-contracted state. In order to elucidate the mechanisms of K+induced relaxation and compare with that of 2-kidney, 1 clip (2K1C) renal hypertensive rats, we recorded aortic vascular tension using an organ bath study.METHOD:
2K1C hypertension was made by clipping the left renal artery and age-matched control rats received a sham treatment. Thoracic aortic rings were mounted in tissue baths for measurement of isometric contractile force.RESULTS:
Exposure to K+(from 2 to 8 mM) relaxed a phenylephrine (2 x 10-6 M)-induced contraction in K+free Krebs-Ringer solution, dose-dependently. Ouabain (10-5 M) enhanced the K+induced relaxation in above 2 mM K+ The K+induced relaxation was still induced in endothelium-denuded condition. Incubation with the K+channel blockers such as tetraethylammonium (TEA, 1 mM), glibenclamide (10-5 M), 4-aminopyridine (3 mM), barium (5 mM) and cesium (2 mM) did not affect on the K+induced relaxation. In renal hypertensive rats, the K+induced relaxation was markedly suppressed and ouabain enhanced it.CONCLUSIONS:
These results suggest that the K+induced relaxation in aorta be mediated by Na-pump independent mechanisms, and the decrease of the K+induced relaxation in the renal hypertensive rats may be a possible mechanism of hypertension.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Aorta
/
Ouabaína
/
Fenilefrina
/
Placebos
/
Relaxamento
/
Artéria Renal
/
Bário
/
Vasodilatação
/
Banhos
/
4-Aminopiridina
Limite:
Animais
Idioma:
Coreano
Revista:
Korean Circulation Journal
Ano de publicação:
2000
Tipo de documento:
Artigo
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