CURRENT SMOKING OF ELDERLY MEN REDUCES ANTIOXIDANTS IN ALVEOLAR MACROPHAGES

Alveolar macrophages were prepared from 15 healthy elderly male curren t smokers 60.9 +/- 9.9 yr of age (mean +/- SD), Alveolar macrophages f rom 11 elderly male nonsmokers 66.7 +/- 8.1 yr of age served as contro ls. Production of oxygen radical species was higher in alveolar macrop hages from current smokers than in those from nonsmokers in the presen ce and absence of phorbol myristate acetate (29.8 +/- 15.5 versus 13.7 +/- 8.2 mu mol/10(6) cells and 3.8 +/- 1.6 versus 2.2 +/- 1.2 mu mol/ 10(6) cells, respectively, p < 0.01). Decreases in antioxidant activit y were observed in cells from smokers versus those from nonsmokers for Cu, Zn-superoxide dismutase (114 +/- 41 versus 210 +/- 73 units/mg pr otein, respectively, p < 0.01), glutathione S-transferase (0.217 +/- 0 .091 versus 0.368 +/- 0.017 units/mg protein, p < 0.01), and glutathio ne peroxidase (0.736 +/- 0.779 versus 1.590 +/- 0.879 units/mg protein , p < 0.05). Immunologic estimation showed a decrease in the levels of Cu, Zn-superoxide dismutase in cells from smokers (104.3 +/- 46.4 ver sus 184.1 +/- 64.4 ng enzyme/mg protein, respectively, p < 0.01). Nort hern blot analysis of Cu, Zn-superoxide dismutase mRNA showed no appar ent difference between the two groups, suggesting not the inactivation of this enzyme but a reduction of the translational step or increased proteolysis. The oxidant and antioxidant imbalance observed in elderl y male current smokers may be a factor in the pathogenesis of respirat ory tissue injury caused by smoking.