Protective role of N-acetylcysteine against the age-related decline in oxidative phosphorylation in pulmonary smooth muscle mitochondria

It has been proposed that oxygen radical inactivation of mitochondrial key enzymes plays a crucial role in the ageing of cells and tissues. In view of this, we sought to determine the effects of a thiolic free radical scavenger, N- acetylcysteine, on the oxidative phosphorylation enzymes of pulmonary smooth muscle mitochondria from male rats. At 40 weeks of age, a control group was fed with standard food pellets and another group received pellets containing 0.25% (w/w) N-acetylcysteine. After 20 weeks treatment, the specific activities of complex I, IV and V in the smooth muscle mitochondria of the N-acetylcysteine-treated animals were significantly higher than those in controls. Med Sci Res 27:39-40 (C) 1999 Lippincott Williams & Wilkins.