Oxygen Radicals Elicit Paralysis and Collapse of Spinal Cord Neuron Growth Cones upon Exposure to Proinflammatory Cytokines

Table 1

Redox-sensitive inhibition of neurite outgrowth in response to TNF𝛼 and IL-1𝛽.

Condition	NL50±SEM	𝑛
Control (10 mg/mL Ov)	147±16 𝜇m	104
TNF𝛼 40 ng/mL	118±6 𝜇m*	74
TNF𝛼 100 ng/mL	86±13 𝜇m*	173
TNF𝛼 100 ng/mL + 10 mM MnTBAP	145±13 𝜇m	62
TNF𝛼 100 ng/mL + 2 mM DPI	113±12 𝜇m**	56
Control (10 mg/mL Ov)	128±7 𝜇m	61
IL-1𝛽 40 ng/mL	109±4 𝜇m*	92
IL-1𝛽 100 ng/mL	80±3 𝜇m*	107
IL-1𝛽 100 ng/mL + 10 mM MnTBAP	112±9 𝜇m**	113
IL-1𝛽 100 ng/mL + 2 mM DPI	87±8 𝜇m*	78
PBS	128±12 𝜇m	156
MnTABP 5 mM	161±10 𝜇m*	82
MnTABP 10 mM	133±7 𝜇m	75
MnTABP 20 mM	115±7 𝜇m*	56
PBS	179±7 𝜇m	103
NAC 2 mM	89±7 𝜇m*	102

SC neuron cultures were incubated with pharmacological inhibitors (MnTBAP, DPI) or PBS prior to addition of cytokines for 6–8 hours. After fixation, the average neurite length of the longest neurite per neuron reached by 50% of neurons (NL₅₀) was quantified for each condition. *Significant differences from controls. **Significant difference from cytokine only at 𝑃<0.05 by one-way ANOVA and Dunnett’s 𝑡-test.