All human retinal endothelial (HRE) cell studies were in accordance with the ARVO and the Charlie Norwood Veterans Affairs Medical Center, research and ethics committee. HRE cells and supplies were purchased from Cell Systems Corporations (Kirkland, WA, USA) and VEC Technology (Rensselaer, NY, USA) as described previously [27 (link)]. Sodium palmitate (catalogue No. P9767; Sigma-Aldrich, St. Louis, MO, USA) was dissolved in 50% ethyl alcohol solution, then added drop-wise to pre-heated 10% endotoxin- and fatty acid-free BSA (catalogue No. A8806; Sigma) in M199 at 50°C to create an intermediate stock solution of palmitate coupled to BSA (Pal-BSA). Confluent cells were switched to serum-free medium for 6 h then treated for 12 h with Pal-BSA solutions in a ratio of 1:10 to produce final concentrations of 200, 400 and 800 μmol/l of Pal-BSA. Equal volumes of 50% ethyl alcohol solution without any palmitate dissolved in BSA served as a control (BSA alone). Peroxynitrite (PN) was purchased from Calbiochem and diluted in 100 mmol/ NaOH and added at a final concentration of 100 μmol/l.