Comparative TNFα, NF
B and MnSOD immunostaining in the MVN and the IVN after a chemical and a mechanical UL. Quantitative analysis of the effects of chemical and mechanical UL on TNFα-Ir cells (A), NFκB-Ir cells (B) and MnSOD-Ir (C) in the MVN and IVN. Data are mean values (± SEM) of the number of positive cells recorded in the chemical UL rats (grey histograms) and in the mechanical UL rats (black histograms) observed at 8 h, 1 and 7 days after the lesions. The data from both sides were pooled for all groups of animals. According to Bonferroni's principle, P < 0.016 was considered significant. * P < 0.016 mechanical versus chemical values.