Quantitation of respiration, H2O2 emission, and electron flow diversion to ROS in isolated heart mitochondria from three different species
| VO2 | H2O2 emissiona | Respiratory flux as H2O2 emissionb | ||||
| State 4 | State 3 | State 4 | State 3 | State 4 | State 3 | |
| nmol/min/mg | nmol/min/mg | nmol/min/mg | nmol/min/mg | % | % | |
| Mouse | 10 ± 2 | 47.5 ± 8 | 1.8 ± 0.03 | 1.2 ± 0.08 | 11 (1 = 11 fold)c | 2.3 (0.17 = 13 fold)c |
| Rat | 35 ± 5 | 202 ± 38 | 1.16 ± 0.03 | 0.55 ± 0.04 | 2 (0.3 = ∼7 fold)c | 0.25 (0.04 = 6 fold)c |
| Guinea pig | 46 ± 2.6 | 152 ± 8.5 | 0.56 ± 0.01 | 0.48 ± 0.06 | 0.74 (0.2 = ∼4 fold)c | 0.29 (0.04 = 7 fold)c |
| VO2 | H2O2 emissiona | Respiratory flux as H2O2 emissionb | ||||
| State 4 | State 3 | State 4 | State 3 | State 4 | State 3 | |
| nmol/min/mg | nmol/min/mg | nmol/min/mg | nmol/min/mg | % | % | |
| Mouse | 10 ± 2 | 47.5 ± 8 | 1.8 ± 0.03 | 1.2 ± 0.08 | 11 (1 = 11 fold)c | 2.3 (0.17 = 13 fold)c |
| Rat | 35 ± 5 | 202 ± 38 | 1.16 ± 0.03 | 0.55 ± 0.04 | 2 (0.3 = ∼7 fold)c | 0.25 (0.04 = 6 fold)c |
| Guinea pig | 46 ± 2.6 | 152 ± 8.5 | 0.56 ± 0.01 | 0.48 ± 0.06 | 0.74 (0.2 = ∼4 fold)c | 0.29 (0.04 = 7 fold)c |
The H2O2 emission fluxes reported are those measured in the presence of both inhibitors simultaneously (50 nM AF + 10 µM DNCB).
The numbers shown correspond to the percentage of the O2 consumption flux diverted to ROS. These values are obtained from calculations using VO2 and H2O2 emission that are in the same units, with the values corrected for the increase in state 4 (60%; Fig. 3 A) and 3 (10%; Fig. 3 B) respiration produced by the presence of AF and DNCB together. For example, in the mouse in state 4 mitochondria, the H2O2 emission (=1.8) represents 11% of the O2 consumption flux (=10 + 6; this latter number is a result of the 60% increase in state 4 respiration, provoked by the presence of both inhibitors simultaneously, i.e., 10 × 0.6 = 6; see Fig. 3 A); thus, 1.8/16 × 100 = 11.2. A similar type of calculation was applied to all other cases.
These values represent the percentage of the respiratory flux diverted to ROS in states 4 and 3 under FET in the absence of inhibitors (see Table 3, Control row).