eNOS uncoupling in senescent endothelial cells.

<p>(<b>A</b>) Immunoblotting analysis of eNOS-dimers and -monomers in the young and senescent HUVEC endothelial cells. Ponseau S staining served as loading control. Quantification of the eNOS-dimer/monomer is shown in the lower panel. n = 4 in each group. *p<0.05. (<b>B</b>) DHE staining for detection of cytoplasmic superoxide generation in young and senescent endothelial cells with or without pre-treatment of the cells with L-NAME (1 mmol/L) for 1 hour as indicated. Quantification of the signals from six independent experiments of each group is shown in the corresponding lower panels. ***p<0.001 between indicated groups. Scale bar = 0.2 mm.