(A) A significant positive correlation was found between serum T level and TNF-α level in the rats (r = 0.8054, P<0.01). (B) RAW 264.7 cells were persistently exposed to different doses of T (0, 10, and 100 nM). The level of TNF-α secreted into the medium decreased significantly at day-1. However, it increased significantly compared to the control at day-3, indicating the bi-directional regulation of T (**three dosages at the same time point, P<0.01 by one-way ANOVA; ##group treated with 0 nM T versus group treated with 10 nM T, P<0.01 by Dunnett’s multiple comparison test; &&group treated with 0 nM T versus group treated with 100 nM T, P<0.01 by Dunnett’s multiple comparison test). (C) The expression of TNF-α mRNA increased after stimulation with T, which restored to the normal levels after day-1 (**three dosages at the same time point, P<0.01 by one-way ANOVA; ##group treated with 0 nM T versus group treated with 10 nM T, P<0.01 by Dunnett’s multiple comparison test; &&group treated with 0 nM T versus group treated with 100 nM T, P<0.01 by Dunnett’s multiple comparison test). (D) The expression of TNF-α protein in the cells treated with T increased significantly at day-1 and day-2.