FIG. 2.

Valproic acid (VPA) inhibits reactive oxygen species (ROS) production and inducible NO synthase (iNOS) expression after spinal cord injury (SCI). Injured rats treated with and without VPA were injected with 200 μL of hydroethidine (HEt) (1 mg/mL) and spinal cord tissues were harvested at 4 h after injury (n=4/group). (A) Representative photomicrographs of HEt fluorescence from the spinal sections taken 2 mm rostral to the lesion epicenter. Arrows indicate HEt-positive neurons in the gray matter (GM). Scale bar, 25 μm. (B) Quantitative analysis of relative ethidium fluoroscence intensity. Spinal samples treated with and not treated with VPA were harvested at 4 h after injury (n=3/group) and then iNOS expression was examined by reverse transcription polymerase chain reaction (RT-PCR) (C, upper), Western blot (C, lower), and quantitative analysis (D). Note that superoxide anion production and iNOS expression were significantly inhibited by VPA after SCI. Total proteins and tissues treated with and not treated with VPA after SCI were prepared at indicated time points. (E and F upper) Western blots and quantification analysis (F lower) of hydroxynonenal (HNE) (n=3/group), (G) double staining with anti-nitrotyrosine and anti-NeuN antibodies, Western blots (H) and quantification analysis (I) of nitrotyrosine at 1 day after injury (n=3/group). Note that VPA significantly decreased SCI-induced increase of HNE at 8 h and 1 day after injury. VPA also alleviated immunoreactivity of nitrotyrosine in the VMN at 1 day after injury. Scale bar, 30 μm. Data represent the mean±SD. *p<0.05, **p<0.01. Color image is available online at www.liebertpub.com/neu