Involvement of MAPK pathways in nitric oxide production by pericytes after LPS stimulation. Brain pericytes were stimulated for 4, 8, and 24 h with LPS (0.1 and 1 ug/ml). MAPK pathway inhibitors were added to the culture medium 1 h before LPS treatment. Media was collected and analyzed for NO production by Griess reaction. Addition of MAPK pathways inhibitors significantly reduced NO production by LPS treated pericytes. Values represent the mean ± SEM of two independent experiments conducted in tetraplicates. *P < 0.05, ***P < 0.001 vs. untreated cells.