Figure 5.
ACE inhibition reduces eNOS glutathionylation and improves endothelium‐dependent vasorelaxation in vivo. A, eNOS expression in aortic homogenates of control and captopril‐treated rabbits. Glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) immunoblot was used as the loading control (n=5 control and 4 captopril‐treated rabbits). B, eNOS glutathionylation in aorta of control and captopril‐treated rabbits (n=5 control and 4 captropril‐treated rabbits). C, O2•−‐sensitive DHE fluorescence in aortic cryosections. Intensity of the signal was measured within the endothelial layer of aorta from control and captopril‐treated rabbits (white arrows, magnified image of the endothelial layer is shown in white boxes; n=5 control and 4 captopril‐treated rabbits, with 5 randomly chosen regions of interest analyzed in each rabbit). D, NO detection in aortic cryosections by DAF2DA (5 μmol/L). Intensity of the signal was measured within the endothelial layer of aorta from control and captopril‐treated rabbits (white arrows, magnified image of the endothelial layer is shown in white boxes) (n=5 control and 4 captopril‐treated rabbits, with 5 randomly chosen regions of interest analyzed in each rabbit). E, Endothelium‐dependent vasorelaxation in aortic rings from control and captopril‐treated rabbits precontracted with PE (100 nmol/L). P value was <0.05 in the captopril‐treated group versus control. PE‐induced precontraction was 2.1±0.2 and 2.0±0.3 g in the control versus captopril group, respectively, and was not statistically different between groups. AU=arbitrary unit. Results are shown as means±SEM. Statistical significance (P<0.05) is indicated by asterisk (*). DHE indicates dihydroethidium; DTT, dithiotreitol; eNOS, endothelial nitric oxide synthase; NO, nitric oxide; PE, phenylephrine.