Fig. 5.

Microglia, but not preOLs, challenged with LPS generated ROS. (A) preOL plus microglia cocultures were treated with or without 0.1 μg/ml LPS. After 24 h, dihydrorhodamine 123 was added at 8 μM for 20 min, and images were taken with a fluorescence microscope to evaluate oxidative stress in microglia and preOLs. Microglia became brightly fluorescent with LPS treatment. Microglia (arrows) and preOLs (arrowheads) were distinguishable by their characteristic morphology. (Scale bar, 20 μm.) (B) Quantification of ROS/peroxynitrite generation was carried out with dichlorohydrofluorescin by using a fluorescence plate reader (mean ± SD, n = 3). l-NMMA, which blocked formation of peroxynitrite by inhibiting NO production, significantly decreased the fluorescence intensity. MG, microglia.