Endogenous ceramide biosynthesis impairs NO generation. BAECs were incubated in the presence (+) or absence (−) of palmitate
(pal) ± myriocin (myr). A: Pal-induced ceramide accrual (n = 6 per treatment). In some experiments, BAECs were treated for the last 10 min with vehicle (veh), insulin (ins), or VEGF.
B and C: Basal (i.e., veh), ins-, or VEGF-stimulated p-eNOS Ser1177 to total eNOS (n = 10–32 per treatment). D: p-eNOS Ser617 (n = 15–19 per treatment). E: p-eNOS Thr495 to total eNOS (n = 10 per treatment). F and G: Ins- or VEGF-stimulated increases in the eNOS dimer to monomer ratio (n = 7–12 per treatment). H: NOS activity (n = 6–7 per treatment). I: Ins-mediated NOx production (n = 10–15 per treatment). *P < 0.05 vs. respective veh treatment; #P < 0.05 vs. (+) ins or (+) VEGF and (−) pal. Results represent mean ± SEM.