Oxygen consumption rates (OCR) of uninfected cells, infected cells and free parasites preparations. The rate of aerobic respiration was determined by the rate of O2 disappearance from an enclosed suspension of biological material. Since differences in the OCR of the tissues may arise due to differences of cell size and associated metabolic demand, the OCR for the host cells are normalised by the ratio of their DNA content to that of the parasite. (Top panel) Comparison of the OCR for uninfected HBMEC cells (H suffix, n = 10), and K562 cells (K suffix, n = 10) and free parasites (P suffix, n = 8) with various exogenous metabolic substrates as indicated. Key: Basal, no substrate; Glu, 10 mM D-glucose; TMPD, 10 mM glucose + TMPD/ascorbate redox couple, Azide as for TMPD + 6mM azide. (Bottom Panel) Comparisons of the OCR for free parasites (P suffix, n = 14), uninfected K562 cells (0 suffix, n = 16), infected cells 1 hr p.i. (1 suffix, n = 8) and infected cells 24 hr p.i. (24 suffix, n = 16) with various exogenous metabolic substrates as shown (n = 8 in all cases). Key: Basal, no substrate; Lac, 10mM D-lactate; MP 10 mM methyl pyruvate. Data in both panels is represented by box and whisker plots where: box, 25% to 75% quartile; bar, 50% quartile (median); whiskers, minimum and maximum.