Respiratory activities of non-infected and C. trachomatis–infected HeLa cells in the presence of respiratory inhibitors and ionophores. Representative traces of oxygen consumption of non-infected (A and C) and infected (B and D) intact HeLa cells in the presence of 1 μm HQNO, rotenone (Rot), oligomycin A (Oligo), or CCCP. Respiratory activities of non-infected (E) and infected (F) digitonin-permeabilized cells were in the presence of NaCl (20 mm), α-ketoglutarate (α-KG, 10 mm), and ADP (0.5 mm). G, oxygen consumption rates of non-infected (upper panel) and infected (lower panel) HeLa cells in the presence of 1 mm KCN or 1 μm of each of the following uncouplers or inhibitors: rotenone, antimycin A (AA), oligomycin A, CCCP, monensin (Mon), and HQNO. H, HQNO titration of rotenone-insensitive respiration of intact infected cells. *, p < 0.05 versus vehicle-treated control (Con).