Fig. 1.

Papaverine reduces OCR by inhibition of mitochondrial complex I. (A) Representative Seahorse data showing decreased OCR in EO771 cells. (B) Competition assay between papaverine and rotenone injected as indicated in EO771 cells. (C) Succinate rescue assay in permeabilized EO771 cells. PPV or rotenone were injected alone or in combination with complex III inhibitor antimycin A (AntA) at time A; succinate (Succ) was injected at time B. (D) Dose–response analysis in A549 cell line. (E) Drug washout experiment in A549 cells, the OCR reduction at 3 h of 10 μM PPV or 1 μM rotenone (magenta), and after removal at T-2 h (blue) or 1 h (black). Error bars represent SD.