Figure 4. Effects of SOD and catalase on K⁺ currents.

A, superoxide dismutase (SOD, 300 U ml⁻¹, 5–9 h) significantly augments K⁺ currents in myocytes from male diabetic rats. Mean I_peak (left) and I_sus (right) current densities (at +50 mV) are shown in the absence (open bars) and presence (hatched bars) of PEG-SOD. **P < 0.005; ***P < 0.0005. B, in contrast, catalase (500 U ml⁻¹, 5–9 h exposure) has no effect on I_peak (left) or I_sus (right).