Fig. 4. Reduction of [Cl⁻]_i limits ROS generation and NADPH oxidase activity in HUVECs.

ROS generation was detected in HUVECs cultured with normal Cl⁻ and low Cl⁻ medium by staining with H₂DCF-DA (a, b) and DHE (c, d). Representative pictures of H₂DCF-DA (a) and DHE (c) staining are shown. Scale bars = 200 μm. Quantitative analysis of H₂DCF-DA (b) and DHE (d) fluorescence intensity. e Bar charts showing the activity of NADPH oxidase in HUVECs cultured with normal Cl⁻ and lower Cl⁻ medium containing VEGF (50 ng/mL) treatment for 48 h. **P < 0.01 vs. normal Cl⁻; ^##P < 0.01 vs. normal Cl⁻ + VEGF, n = 6.