Early Decrease in Respiration and Uncoupling Event Independent of Cytochrome c Release in PC12 Cells Undergoing Apoptosis
Figure 1
Decrease in endogenous, DNP-uncoupled, and TMPD-dependent respiration rates in intact PC12 cells treated with STS; early decrease in DNP-uncoupled respiration. (a) Oxygen consumption rates of 2 μM STS-treated PC12 cells measured at the indicated time points. Oxygen consumption rates were measured in TD buffer (endogenous respiration, End), in TD buffer containing DNP (DNP-uncoupled respiration, DNP) and in TD buffer containing DNP, antimycin A, ascorbate, and TMPD (TMPD-dependent respiration, TMPD). Data are expressed, at each time point, as percentages of the oxygen consumption of untreated cells (0 hr). To reduce the variability of the experiments we calculated the percentages with respect to the control of that particular experiment, and then we averaged the percentages. Data are expressed as means ± SE (standard error) with varying at each time point and being 31, 16, 9, 6, 7, 2, and 7, respectively, for the indicated time points (1 h, 2 h, 3 h, 5 h, 9 h, 24 h). (b) Magnification of (a) area surrounded by a yellow frame. Note that the ordinate scale starts at 50%.
