Omeprazole suppresses endothelial calcium response and eNOS Ser1177 phosphorylation in porcine aortic endothelial cells.

Our results are the first to indicate that high doses of omeprazole may suppress both store-operated Ca2+ channels and partially the G protein-coupled receptor/phospholipase C/inositol 1,4,5-triphosphate pathway, and decreased BK-induced, Ca2+-dependent phosphorylation of eNOS(Ser1177). Thus, high dosages of omeprazole impaired EDRF production by attenuating intracellular Ca2+ signaling.