Effect of endothelin-1 on cytosolic calcium ions in cultured human endothelial cells.
The effects of endothelin-1 on cytosolic Ca2+ and inositol 1,4,5-triphosphate (IP3) levels were investigated in cultured, untreated human endothelial cells and in endothelial cells pretreated with anti-endothelin-1 serum for 24 h to exclude the effect of endogenous endothelin-1. Endothelin-1 was found to increase the intracellular Ca2+ level, either in the presence or absence of extracellular Ca2+, in endothelial cells pretreated with antiserum by the fura-2 fluorescence technique. IP3 levels immediately started to rise following endothelin-1 stimulation. Resting intracellular Ca2+ levels were significantly lower when the cells were pretreated with antiserum than without antiserum pretreatment. Following stimulation by endothelin-1, intracellular Ca2+ and IP3 levels in endothelial cells pretreated with antiserum increased significantly compared to those in untreated endothelial cells. Endothelin-1 also increased 45Ca influx from the extracellular space. These results suggest that endothelin-1 increases intracellular Ca2+ in endothelial cells through extracellular Ca2(+)-dependent mechanisms and by the release of Ca2+ from intracellular stores, this presumably being induced by IP3 formation.
Yokokawa
K
K
First Department of Internal Medicine, Osaka City University Medical School, Japan.
Kohno
M
M
Murakawa
K
K
Yasunari
K
K
Takeda
T
T
D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D016232:Endothelins / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D016257:Fura-2; D006801:Humans; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D002121:Calcium Channel Blockers; D016232:Endothelins; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium; D016257:Fura-2