The effect of Cp in microglial activation depends on the presence of inducible nitric oxide synthase (iNOS). (A) Nitrite production assessed by Griess assay in culture medium of microglial cells after 24 hours of treatment with medium alone (Ctrl), LPS (10 ng/ml), IL-1Β and TNF-Α (2-CKs), or with IL-1Β, TNF-Α and IFN-γ (3-CKs) alone or in combination with ceruloplasmin (Cp) (20 μg/ml). Results are expressed as μM of nitrite present in culture medium that reflects the nitric oxide (NO)-production. (B) Western blot analysis of iNOS expression in microglial cells after treatments as in (A). Densitometric optical density (OD) for iNOS bands were normalized with α-tubulin expression and are reported as ratio of the OD of specific treatments versus OD of LPS treatment. Bottom panels are representative of one experiment. Three/four independent experiments (as indicated n =) were performed and mean values, calculated using pooled data from different experiments, with standard error are reported. Statistical P-values were evaluated by non-parametric Mann-Whitney test. In all analyses, P < 0.05 was considered to be statistically significant.