TNF-α induced transient KCa current activation occurs due a ROS elevation. A, TNF-α (50 ng/ml)-induced transient KCa current activation was reversed by MnTMPyP. B, C, Mean transient KCa current frequency and amplitude. TNF-α (50 ng/ml, n=12), TNF-α + MnTMPyP (10 μM, n=6), TNF-α with catalase (Cat, 200 U/ml, n=6), TNF-α with boiled catalase (Boil. catalase, 200 U/ml, n=6). * P<0.05 when compared with control. # P<0.05 when compared with TNF-α.