Table 1.

Oxygen consumption by mitochondrial respiratory components

Substrate + inhibitor	ECV304	ECV304 ρ−	ECV304+eNOS	ECV304+eNOS ρ−
Pyruvate + malate	3.0  ± 0.7	0.3  ± 0.1*	1.7  ± 0.8	1.2  ± 0.4
Succinate + rotenone	2.5  ± 0.5	0.4  ± 0.2*	1.7  ± 1.0	0.4  ± 0.2**
Ascorbate/TMPD + antimycin	5.9  ± 1.3	2.3  ± 1.0*	3.6  ± 0.3	1.3  ± 0.4**

ADP-stimulated oxygen consumption by mitochondrial complexes I, III, and IV was performed in digitonin-permeable cells with the addition of 10 mM pyruvate and 2 mM malate, and complexes II, III, and IV with 10 mM succinate plus 10 μM rotenone. Azide-sensitive cytochrome oxidase activity (complex IV) was measured by using 3 mM ascorbate plus 0.3 mM TMPD in the presence of 2 μM antimycin. Oxygen consumption is expressed as nAO/min/10⁶ cells and the data represent means ± SD of 3–8 independent determinations. 

^*, Statistically significant at P < 0.05 from ECV304; 

^**, statistically significant at P < 0.05 from ECV304+eNOS.