Figure 3

Activation (phosphorylation) of spinal ERK1/2 after saline or minocycline pretreatment. (A) Western blots of spinal tissue (T5-L2). N, normal. AA, saline-pretreated and acetic acid-treated mice, M, minocycline alone. M + A, minocycline-pretreated and acetic acid-treated mice. (B-D) Immunohistochemistry of spinal tissue from normal animals (B), saline-pretreated and acetic acid-treated mice (C), minocycline-pretreated and acetic acid-treated mice (D). Insets are high magnification of the open rectangles. The scale bar denotes 100 μm. (E) The number of p-ERK positive cells in spinal cord (T5-L2) following minocycline pre-injection. The enhancement in the number of p-ERK positive cells produced by acetic acid was significantly decreased in spinal cord by minocycline pre-administration. The mean number of p-ERK positive cells was calculated by averaging the total numbers of each region per each section/region. Values are expressed mean ± SEM. ⁺, p < 0.01 versus normal group; *, p < 0.01 and **, p < 0.05 versus control group (ANOVA test with a Fisher's post hoc test)