Xestospongins, a group of macrocyclic bis-1-oxaquinolizidines isolated from the Australian sponge, Xestospongia species, are potent blockers of the inositol 1,4,5-trisphosphate (IP(3))-induced Ca2+ release in bi-directional Ca2+-flux conditions. We have now studied the effects of xestospongin C on the (45)Ca2+ uptake and the uni-directional (45)Ca2+ efflux in permeabilized A7r5 smooth-muscle cells. Xestospongin C not only inhibits the IP(3)-induced Ca2+ release, but is also an equally potent blocker of the endoplasmic-reticulum Ca2+ pump, while it has no effect on the passive Ca2+ leak. The inhibition of the IP(3) receptor did not depend on the IP(3), Ca2+ or ATP concentration. Xestospongin C can, therefore, not be considered as a selective blocker of IP(3) receptors.
De Smet, P., Parys, J.B., Callewaert, G., Weidema, A.F., Hill, E., De Smedt, H., et al. (1999). Xestospongin C is an equally potent inhibitor of the inositol 1,4,5-trisphosphate receptor and the endoplasmic-reticulum Ca(2+) pumps. CELL CALCIUM, 26(1-2), 9-13 [10.1054/ceca.1999.0047].
Xestospongin C is an equally potent inhibitor of the inositol 1,4,5-trisphosphate receptor and the endoplasmic-reticulum Ca(2+) pumps
Sorrentino, V.;
1999-01-01
Abstract
Xestospongins, a group of macrocyclic bis-1-oxaquinolizidines isolated from the Australian sponge, Xestospongia species, are potent blockers of the inositol 1,4,5-trisphosphate (IP(3))-induced Ca2+ release in bi-directional Ca2+-flux conditions. We have now studied the effects of xestospongin C on the (45)Ca2+ uptake and the uni-directional (45)Ca2+ efflux in permeabilized A7r5 smooth-muscle cells. Xestospongin C not only inhibits the IP(3)-induced Ca2+ release, but is also an equally potent blocker of the endoplasmic-reticulum Ca2+ pump, while it has no effect on the passive Ca2+ leak. The inhibition of the IP(3) receptor did not depend on the IP(3), Ca2+ or ATP concentration. Xestospongin C can, therefore, not be considered as a selective blocker of IP(3) receptors.File | Dimensione | Formato | |
---|---|---|---|
xesto.pdf
non disponibili
Tipologia:
PDF editoriale
Licenza:
NON PUBBLICO - Accesso privato/ristretto
Dimensione
134.34 kB
Formato
Adobe PDF
|
134.34 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11365/21132
Attenzione
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo