Intracellular smooth muscle [Ca2+] in acetylcholine and nitric oxide-mediated relaxation of human small arteries.
Eur J Pharmacol
; 535(1-3): 243-7, 2006 Mar 27.
Article
en En
| MEDLINE
| ID: mdl-16522319
ABSTRACT
In human resistance arteries the role of intracellular calcium during receptor agonist and nitric oxide (NO)-mediated vasorelaxation is almost unknown. We examined changes in smooth muscle calcium concentration ([Ca2+]i) caused by acetylcholine and the NO donor S-nitroso-N-acetylpenicillamine (SNAP) in isolated human subcutaneous small arteries. In arteries constricted with 50 mM KCl, acetylcholine and SNAP induced relaxation without any change in [Ca2+]i, whereas in noradrenaline constricted vessels, both acetylcholine and to a lesser degree also SNAP-mediated relaxation were associated with a decrease in [Ca2+]i. Furthermore incubation with SNAP (1 microM) induced a rightward shift in the [Ca2+]i-force relationship. These results suggest that relaxation mediated by endothelium derived hyperpolarizing factors (EDHF) is associated with reduction in [Ca2+]i, whereas NO-mediated relaxation can take place without changes in [Ca2+]i. This finding seems to be, at least partly, due to NO-mediated desensitization of the contractile apparatus to calcium.
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Bases de datos:
MEDLINE
Asunto principal:
Arterias
/
Vasodilatación
/
Acetilcolina
/
Calcio
/
Músculo Liso Vascular
/
Óxido Nítrico
Límite:
Humans
Idioma:
En
Revista:
Eur J Pharmacol
Año:
2006
Tipo del documento:
Article
País de afiliación:
Dinamarca