Figure 6. Effects of short-term treatment with sorafenib on mitochondrial respiratory function in HepG2 cells. (A, B) Representative tracings of high-resolution respirometry in intact HepG2 cells in the presence or absence of short-term treatment (15 min) with IC80 of sorafenib (A), and the statistical results of mitochondrial respiratory parameters (B). O2 flow per 106 cells (green line for HepG2 cells in the presence of sorafenib and red line for control cells) and O2 concentration (blue line for HepG2 cells in the presence of sorafenib and yellow line for control cells) were recorded in real time. OMY, oligomycin; FCCP, carbonylcyanide-4-(trifluoromethoxy)-phenylhydrazon; ROT, rotenone; AMA, antimycin A. (C) Representative tracings of the effects of short-term treatment with IC20 of sorafenib on the OXPHOS system in permeabilized HepG2 cells. DIG, digitonin; PM, pyruvic acid + L-malic acid; G, glutamate; S, succinate; FCCP, carbonylcyanide-4-(trifluoromethoxy)-phenylhydrazon; ROT, rotenone; AMA, antimycin A; CI, Complex I; CII, Complex II; OXPHOS, oxidative phosphorylation; ETS, electron transfer system; ROX, residual oxygen consumption. (D1–D7) Summarized OXPHOS analysis. CI Leak, leak respiration of CI; CII OXPHOS = CI&CII OXPHOS − CI OXPHOS; CI ETS = CI&CII ETS − CII ETS. All data are presented as the mean ± SD; *p < 0.05, **p < 0.01 by unpaired, two-tailed Student’s t test. Experiments were repeated 3 times.