Involvement of two-pore channels in hydrogen peroxide-induced increase in the level of calcium ions in the cytoplasm of human umbilical vein endothelial cells.

Hydrogen peroxide at concentrations below cytotoxic ones causes an increase in the cytoplasmic calcium concentration in human umbilical vein endothelial cells as a result of calcium release from intracellular stores. Two-pore calcium channel blocker trans-NED19 partially suppresses the increase in the level of calcium ions in the cells in response to the addition of hydrogen peroxide. The staining of endothelial cells with the fluorescent stereoisomer cis-NED19 and LysoTracker confirmed the localization of two-pore calcium channels in lysosomes and endolysosomal vesicles.