Effect of genetic or pharmacological inhibition of iNOS on Thiobarbituric acid-reactant substances, a good indicator of lipid peroxidation, in the lung. Thiobarbituric acid-reactant substances levels in the lungs of bleomycin-treated iNOSWT mice were significantly increased in comparison to sham-operated mice. The genetic or pharmacological inhibition of iNOS significantly reduced the bleomycin-induced increase in Thiobarbituric acid-reactant substances levels. Data are means ± s.e. means from 10 mice for each group. *p < 0.01 versus sham. °p < 0.01 represents significant reduction of the various parameters in the group in which iNOS was inhibited or absent.