Fig. 4.

Effect of antioxidants on prorenin-induced ENaC activity. A: mpkCCD cells were pretreated for 30 min with vehicle, apocynin (10 μM), tempol (2 mM), or tempol (2 mM) + catalase (1 μg/ml) and then treated with 10 nM prorenin. Amiloride-sensitive I_eq was taken as ENaC activity. B: mpkCCD cells were treated with vehicle, apocynin, tempol, or catalase alone at the same concentrations. C: time course of I_eq changes in control, prorenin, and prorenin + tempol groups. D: amiloride-sensitive I_eq in mpkCCD cells exposed to 1.5 μM H₂0₂ for 1 min. Data are means ± SE; n = 6–12 per group. *P < 0.05 vs. basal in the same group; #P < 0.05 vs. prorenin.