Table 2. Synaptosomal Respiration Measured by Clark Electrode Oxygraph Compared to the XF24a.
| condition | XF24 noncorrected oxygen consumption rate (nmol O/mg protein) | XF24 corrected oxygen consumption rate (nmol O/mg protein) | Clark electrode oxygen consumption rate (nmol O/mg protein) |
|---|---|---|---|
| basal respiration (glucose) | 6.25 ± 0.51 | 34.3 ± 1.5 | 54.6 ± 2.7b |
| oligomycin (2 μg/mL) | 4.31 ± 0.23 | 23.9 ± 0.9 | 32.5 ± 4.0ns |
| FCCP (4 μΜ) | 29.3 ± 2.4 | 157 ± 14 | 140.8 ± 7.6ns |
| succinate + cytochrome c | 61.0 ± 3.1 | 318 ± 18 | 267.8 ± 9.3ns |
a
Oxygen consumption rate is given as mean ± sem per mg of unlysed synaptosomal protein determined by Bradford assay from n = 3 synaptosomal preparations. The non-corrected oxygen consumption rate is given as −d[O2]M/dt times VC = 7 μl (geometric volume of entrapped medium in XF24 V7 microplates). Corrected oxygen consumption rate in the polystyrene XF24 V7 microplates was determined using the time constants in Table 1 and using VC = 22.7 μl. ns, not significant.
b
p < 0.05 significance by paired t-test comparing corrected oxygen consumption rate and Clark electrode values.