Figure 4

NAC restores gp 120-related decrease of GS expression. Glutamine synthase staining in astroglial cells either untreated or treated with gp 120 (10 nM) and gp 120 plus NAC (5 mM) for 24 hours. In particular, gp 120 reduced the immunocytochemical expression of glutamine synthase, while pre-incubation of cells with NAC restores gp 120- related decrease of GS in astrocytes. These are representative photomicrographs out of five independent experiments.