A delayed and sustained rise of cytosolic calcium is elicited by oxidized LDL in cultured bovine aortic endothelial cells

Bovine aortic endothelial cells (BAEC) pulsed for 5 h with mildly oxidized low density lipoproteins (LDL), exhibited a broad, sustained and high peak of [Ca2+]i occurring several hours after the end of the pulse and reaching very high [Ca2+]i values (around 2500-3000 nmol/l) and a concomitant drop of cytosolic pH (around 0.2-0.3 pH units) without any loss of cell viability. When BAEC were continuously pulsed with oxidized LDL, the peak of [Ca2+]i was more sustained than in short pulse experiments and was associated with irreversible morphological changes usually associated with cytotoxic events (blebbing) and with a marked loss of viability. The potential involvement of these biochemical and morphological changes in atherogenesis are discussed.