The Chemical Interplay between Nitric Oxide and Mitochondrial Cytochrome c Oxidase: Reactions, Effectors and Pathophysiology
Figure 4
Oxygen consumption of Ataxia Telangiectasia (AT) cells: the inhibitory effect of NO. (a)—O2 consumption profiles of AT and control lymphoblastoid cells, recorded in the dark and in the presence of excess ascorbate and tetramethyl-p-phenylenediamine (TMPD). Inhibition of respiration was induced by adding a single bolus of pure NO gas solution (see lower NO profiles). In order to assess the fraction of residual inhibited CcOX-NO, the instantaneous rate was measured at 45 s after HbO2 addition. (b)—First derivative plots (integration time s). Rate of O2 consumption before addition of NO (), and after addition of oxygenated hemoglobin, HbO2 (), that is, in the absence of free NO. In: inhibited state (in the presence of free NO). The value is the time necessary for complete recovery of activity after addition of HbO2. °C. (c)—Cytochrome c immunoblot. Cell-lysate (30 μg/well) of AT patients and controls (ctr). (d)—Relative contribution of OXPHOS and glycolysis to ATP production in AT and control cells. Modified from [57].
