AGE-RELATED-CHANGES IN THE ANTIOXIDANT SCREEN OF THE DISTAL LUNG IN MICE

We studied the influence of age on glutathione (GSH) content in the di stal lung and the lung tissue of mice. From 1 to 28 months of age, the quantity of GSH and glutathione disulfide (GSSG) in bronchoalveolar l avage (BAL) fluid and in the lung tissue were determined. The GSH cont ent in BAL fluid, which reflects the antioxidant screen of the distal lung, decreased with advancing age. The ratio of GSSG to GSH increased in later life, suggesting increase of oxidation of the epithelial lin ing fluid in old mice. The GSH content in the lung tissue also decreas ed with aging. Therefore the lower respiratory tract may be less able to defend against external attack, including attack by oxygen-derived active molecules, in senescent mice. The decrease of the antioxidant s creen of the distal lung may be associated with impaired lung defense in relation to oxidant-antioxidant balance in aged mice.