Fig. 6.
BzATP enhances NO production induced by IL-1β plus IFNγ. Expression of NOS2 in astrocytes was induced by activation with 10 ng/ml IL-1β and IFNγ (I/I) for 72h. A—D: Immunohistochemical analysis of NOS2 immunoreactivity in (A) resting astrocytes, (B) cells treated for 72 h with I/I alone, (C) cells co-treated with 100 BzATP, or (D) cells pretreated with 10 nM KN-62 before BzATP and cytokine addition. E: Cells were treated with P2 receptor agonists as shown and nitrite concentrations determined using the Griess reagent. Statistical analysis revealed no significance except for P < 0.01 (**) for BzATP compared with I/I alone and P < 0.05 (*) for ADP compared with I/I alone by Dunnett’s multiple comparison test. F: Cells were treated with increasing doses of BzATP as shown and nitrite concentrations determined as above. Statistical analysis revealed increasing significance with increasing dose, P < 0.05 (*), 0.01 (**) and 0.001 (***) for 10, 100, and 300 μM, respectively, by one-way ANOVA. G: Cells were treated with I/I and varying BzATP doses with or without 10 nM KN-62 pretreatment for 72 h and nitrite concentrations determined. Data are shown as a percentage of I/I alone. BzATP effects were diminished by KN-62 pretreatment for 100 and 300 μM BzATP, P < 0.05 (*) and P < 0.01 (**) by Bonferroni post test (pooled data from three cases, six wells per case).