Fig. 3.

Levels of cytokines and expression patterns of the corresponding receptors in the periaqueductal gray (PAG), and pain responses after receptor blocking. (A-C) Classical proinflammatory cytokines levels, the expression patterns of their receptors, and typical bands. There were increased levels of inflammatory cytokines and their receptors (interleukin [IL]-1R, IL-6R, and tumor necrosis factor receptor 1 [TNFR1]) in streptozotocin (STZ) rats (n = 12). (D-F) After blocking their receptors, paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) appeared to be reduced in STZ rats (n = 10) compared with control animals (n = 12). The error bars indicate standard deviation. ^aP < 0.01 vs. control rats. ^bP < 0.05 and ^cP < 0.01 vs. STZ rats.