Figure 2

IgG reduces neutrophil extravasation. (A) Myeloperoxidase (MPO) activity was detected in sham (n = 4), intravenous saline (saline, n = 9), and intravenous IgG (IgG, n = 8) groups. MPO was used to indirectly measure the presence of neutrophils 24 h after SCI. IgG-treatment significantly reduced MPO activity relative to saline control (ANOVA P <0.05, Bonferroni post-hoc test P = 0.009). (B) Representative fluorescence images demonstrate neutrophil distribution at the injury epicenter in the spinal cord at 24 h post SCI (PMN; green). Neutrophils were observed in both saline and IgG-treated animals. (C) A representative confocal image of neutrophils (PMN; green) and DAPI (blue) was taken from the indicated area (smaller box), and the scale bar represents 75 μm in length. (D) Stereological cell counts demonstrated significantly fewer neutrophils in IgG-treated animals relative to saline control injected animals across 3,000 μm of the injured spinal cord (one-way ANOVA P <0.001; Bonferroni post-hoc test P = 0.011). Error bars represent SEM.