Differential vasorelaxant effects of levcromakalim and P1060 in the isolated KCl- and RbCl-precontracted human saphenous vein: possible involvement of intracellular Ca2+ stores.
Eur J Pharmacol
; 286(2): 123-30, 1995 Nov 14.
Article
en En
| MEDLINE
| ID: mdl-8605948
ABSTRACT
The influence of rubidium-substituted physiological salt solution (Rb-PSS) on the relaxant effects of K+ channel openers was investigated in the human saphenous vein. In tissues precontracted with 20 mM KCl (in K-PSS) levcromakalim and P1060 produced complete, sustained relaxations. However, in Rb-PSS (containing 20 mM RbCl) these effects were inhibited and, although complete relaxations still occurred, were transient. When caffeine was applied at the beginning of this fade of levcromakalim-induced relaxation in Rb-PSS its contractile effect was potentiated. Similarly, the contraction to noradrenaline was potentiated when applied at the beginning of this fade of levcromakalim-induced relaxation, whereas this response was attenuated in control tissues bathed in 20 mM KCl (in K-PSS). Our results show that the relaxant effects of K+ channel openers in human saphenous vein are inhibited in Rb-PSS, in agreement with previous studies in animal tissue, and suggest that an increased Ca2+ uptake into intracellular stores may be contributory to vasorelaxation.
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Banco de datos:
MEDLINE
Asunto principal:
Pirroles
/
Vasodilatadores
/
Benzopiranos
/
Canales de Potasio
/
Calcio
/
Guanidinas
Límite:
Humans
Idioma:
En
Año:
1995
Tipo del documento:
Article