Involvement of Ca2+ in the H2O2-induced increase in endothelial permeability

Hydrogen peroxide-induced increase in Ca2+ determines the increased permeability of endothelium. Hydrogen peroxide increases the Ca2+ intake within 10 seconds of loading the bovine pulmonary microvessel endothelial cells (BMVEC) with Ca2+ sensitive membrane permeant fluorescent dye fura 2-AM. Pretreatment of BMVEC monolayers with Ca2+ chelator, BAPTA-AM (1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl) decreases hydrogen peroxide-induced increase in endothelial permeability. This increase is independent of Ca2+ influx.