Role of endothelium-derived hyperpolarizing factor in shear stress-induced endothelium-dependent relaxations of rats / 药学学报
Acta Pharmaceutica Sinica
;
(12): 491-495, 2005.
Article
Dans Chinois
| WPRIM
| ID: wpr-353487
ABSTRACT
<p><b>AIM</b>To investigate the role and mechanism of endothelium-derived hyperpolarizing factor (EDHF) in shear stress induced vasorelaxation of rat mesenteric artery.</p><p><b>METHODS</b>The changes in vessel diameter in response to variable flow (0-300 microL.min(-1)) were continuously examined. The contribution of prostacyclin (PGI2), NO and EDHF to shear stress induced relaxation were analyzed by inhibitory effects of indomethacin, N(G)-nitro-L-arginine (L-NA) and KCl. The nature and hyperpolarizing mechanism of EDHF were examined by the inhibitory effects of inhibitors of cytochrome P450 pathway and of various K+ channels.</p><p><b>RESULTS</b>The shear stress-induced relaxation were endothelium dependent and the contribution of NO was more prominent in large mesenteric arteries (400-500 microm) than that in resistance arteries (150-250 microm), whereas that of EDHF was noted in both-sized blood vessels. Tetrabutylammonium (a nonselective inhibitor of K channels) almost abolished, whereas the combination of charybdotoxin (an inhibitor of both large and intermediate-conductance Ca2+-activated K channels) and apamin (an inhibitor of small-conductance Ca2+-activated K channels) significantly inhibited the EDHF-mediated component of the shear stress-induced relaxations.</p><p><b>CONCLUSION</b>EDHF plays an important role in shear stress-induced endothelium-dependent relaxations, and K channels especially calcium-activated K channels appear to be involved.</p>
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Apamine
/
Pharmacologie
/
Physiologie
/
Proadifène
/
Vasodilatation
/
Techniques in vitro
/
Endothélium vasculaire
/
Facteurs biologiques
/
Rat Wistar
/
Charybdotoxine
Limites du sujet:
Animaux
langue:
Chinois
Texte intégral:
Acta Pharmaceutica Sinica
Année:
2005
Type:
Article
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