Values are means ± SEM (n = 10). The data include 10 isolated lung preparations. *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. PMA, phorbol myristate acetate; and NAC, niacinamide. The symbols 0 and 4 denote the dose of PMA at μg/g (lung weight), and 0, 100, 200 and 400 of NAC at mg/g (lung weight). The expression of glyceraldehyde phosphate dehydrogenase (GAPDH) was used as an internal standard.