Ionomycin

Ionomycin (56092-81-0) is a highly selective nonfluorescent calcium (Ca2+) ionophore.(1) Induces a rapid rise in cytosolic Ca2+ in human neutrophils which is due to both release from cytosolic Ca2+ stores as well as Ca2+ influx.(2) It activates (2 μM) and primes (20-200 nM) neutrophil NADPH oxidase (2). Down regulates beta-catenin/Tcf signaling in a colon cancer cell line via suppressing the binding of Tcf to its specific DNA-binding site.(3) In rat hepatoma cells, sub-lethal ionomycin activates the stress response by activating SAPK/JNK and HSF/HSE interaction leading to upregulation of HSP70 biosynthesis.(4)