M-1 cells were incubated with prorenin and renin (10-12, 10-10 , 10-8 , 10-6 M). ROS production was measured after 10 min using DCFHDA probe and levels of DCF formed (nM/μg total protein). ROS formation was augmented by prorenin at 10-8 M. Renin increases ROS formation at non-physiological dose (10-5 M). P-coumaric acid (PCA, 10-7 M) added 10 min before prorenin treatment prevented the induction of ROS. As a positive control 200 mM H2O2 was used. *P<0.05 versus control, ***P<0.001 versus control, n=12.