Fig. 4.

The MPP⁺-induced production of superoxide anion and decrease of mitochondrial membrane potential in CATH.a cells were attenuated by LSA. CATH.a cells were either cultured with 300 μM MPP⁺ for various time-periods or pretreated with 100 μM LSA for 30 min, and then were cultured with 300 μM MPP⁺ for 120 min. After treatments, superoxide anion and mitochondrial membrane potential were detected by the fluorescence of hydroethidine (HEt) and TMRM, respectively. The representative images are shown in panel (a). Panel (b) is the relative fluorescence (% of control) of TMRM (opened bars) and HEt (closed bars). Results are means ± S.D. from three independent experiments. Significant differences between the cells treated with vehicle and MPP⁺ were indicated by *, P < 0.05, ***, P < 0.001. Significant differences between the cells treated with 300 μM MPP⁺ alone (C) and 300 μM MPP⁺ combined with LSA were indicated by #, P < 0.05; ##, P < 0.01