Oxidized low-density lipoprotein stimulates nitric oxide release by rabbit aortic endothelial cells.

Incubation of rabbit aortic endothelial cells (RAEC) with oxidized low-density lipoprotein (LDL) for 16 h resulted in stimulation of calcium uptake and increased release of nitric oxide (NO) by these cells. Accompanying inhibition of protein tyrosine phosphatase (PTP) activity in these cells was also observed. Conversely, native LDL was unable to produce any of those effects. These observations suggest that oxidized LDL could modulate two major signalling processes in endothelial cells: tyrosine dephosphorylation and NO synthesis. Such modulation may be of importance in the early phase of the atherogenic process.