The lung weight (LW) to body weight (BW) ratio (A), LW gain (LWG, B), exhaled nitric oxide (NO, C), and protein concentration in bronchoalveolar lavage (PCBAL, D). Phorbol myristate acetate (PMA) significantly increased these lung variables. Administration of niacinamide (NAC) attenuated the PMA-induced changes in a dose-dependent manner. PMA at a dose of 4 μg/g (PMA 4) (lung weight) was given into the lung perfusate. PMA 0 denotes the control lungs without receiving PMA. NAC 0, 100, 200, and 400 indicate the doses of NAC at mg/g (lung weight). *p < 0.05 PMA 4 vs. PMA 0. §p < 0.05 vs. NAC 0 (dose effects of NAC). +p < 0.05 vs. the values of PMA 4. There were 10 isolated lung preparations in each group.