Mitochondrial function and nitric oxide utilization

CARRERAS, MC, SCHÖPFER, F, LISDERO, C, RIOBÓ, N, PODEROSO, JJ

BIOLOGICAL RESEARCH

Año: 2000 vol. 33 p. 175 - 181

0716-9760

Nitric oxide has profound effects on the mitochondrial function. It first appeared to be as an integral mitochondrial regulator of O2 uptake, ATP synthesis (Brookes et al., 1999) and the production of oxygen active species. The inhibitory NO effects on cytochrome oxidase depend on the matrix NO steady-state concentrations and consequently, on NO utilization. In aerobic conditions, nitric oxide decays primarily through a sequence of ubiquinol-centered reactions, ultimately producing peroxynitrite and hydrogen peroxide (Fig 4). Considering the high affinity of NO for cytochrome oxidase, these pathways are important to avoid a sustained inhibition of the mitochondrial transfer chain. Additionally, the mechanism will become a dangerous one, whether or not NO concentration increases in the mitochondrial matrix. The consequence will be the oxidation of proteins and lipids, mitochondrial damage and alterations in the life cycle, as judged by mitochondrial influence on cell apoptosis. (Valdez et al., 2000).