Complex I inhibitor decreases LDH release. HepG2 cells were pretreated with the inhibitor of mitochondrial complex I- rotenone (0.5 μM) for 30 minutes, and then exposed to 0.7 mM palmitate for 24 h. After the treatment, the media were collected and LDH released was measured. The cells were lyzed in 1% triton for 24 h to obtain the unreleased LDH. The LDH released was normalized to the total LDH (released + unreleased). Data presented as average +/- s.d. of n = 9 from three independent experiments. *, significantly lower than palmitate.