Reactive Oxygen Species Mediate Low Back Pain by Upregulating Substance P in Intervertebral Disc Degeneration

Figure 4

SP was the key factor mediating LBP. (a) IHC analysis suggested an increase of SP levels in human NP tissue, with a significant difference among the VAS mild, VAS moderate, and VAS severe groups. (b, c) Administration of SP into the IVDs of rats significantly induced LBP, indicating a decrease in the mechanical allodynia threshold and an increase in the cold allodynia threshold when compared with those of the puncture + saline group, with a dose-dependent response. (d, e) By contrast, administration of the SP receptor inhibitor of aprepitant significantly attenuated LBP in rats. (f) The timeline of drug delivery and behavioral testing for all groups (The data are shown as the . The positive cell with SP was marked with red arrows. , , and for the VAS mild, VAS moderate, and VAS severe groups, respectively. <0.05 and <0.01 for comparisons between the puncture + SP 0.1 μg group and the puncture + saline group. + <0.05 and ++ <0.01 for comparisons between the puncture + SP 1 μg group and the puncture + saline group. × <0.05 for comparisons between the puncture + SP 0.1 μg group and the puncture + SP 1 μg group. ^ <0.05 and ^^ <0.01 for comparisons between the puncture + aprepitant and the puncture + saline group. One-way or two-way ANOVA and Tukey’s multiple comparison test were used for statistical analysis).

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