IDEBENONE INDUCES OXYGEN-CONSUMPTION RATE MODIFICATIONS IN AGED RAT-BRAIN MITOCHONDRIA

Idebenone effects on oxygen consumption in brain mitochondria, obtaine d from young and aged rats, were evaluated. Sixty rats (3 and 20 month s of age) were treated for 3 months with 30 mg/kg of idebenone and com pared to a placebo group. Brain mitochondria oxygen consumption rate w as measured by polarographic techniques in basal (State 4), ADP-stimul ated (State 3) and uncoupled conditions. When Complex I substrates (py ruvate + malate) were used, aged non-treated rats showed a significant increase in State 4 (175%) and uncoupled (152%) O-2-uptake rate; no d ifference was found in State 3 respiration and in ADP/O-2 ratio. Idebe none was able to reverse these age-related effects probably acting on lipid peroxidation and the mitochondrial respiratory chain. No differe nces were found in mitochondrial enzymatic activities. Copyright (C) 1 997 Elsevier Science Ireland Ltd.