Figure 4.

Time course of phospho-p38^MAPK phosphorylation by ammonia in cultured astrocytes. A, Western blot analysis reveals no significant change in total p38^MAPK level when cultures were exposed to 5 mm NH₄Cl. A significant increase in the level of phospho-p38^MAPK was identified when cultures were exposed to NH₄Cl. SB239063, a p38^MAPK inhibitor, prevented the ammonia-induced p38^MAPK phosphorylation. B, Quantitation of ammonia-induced phospho-p38^MAPK levels in the astrocytes. Phospho-p38^MAPK levels are normalized against α-tubulin. ANOVA, n = 4.∗p < 0.05 versus control; ^†p < 0.05 versus phospho-p38^MAPK. Error bars represent mean ± SEM.