Objective To observe the effect of Tuina on the mechanical paw withdrawal threshold (PWT), thermal paw withdrawal latency (PWL), and the expression of interleukin-1β (IL-1β), interleukin-6 (IL-6) and c-Fos in the spinal dorsal horn of neuropathic pain model rats (NP) and to explore the mechanism of Tuina in relieving NP.
Methods 36 male SD rats were randomly divided into blank group, chronic construction injury (CCI) group and CCI + Tuina group, with 12 rats in each group. The CCI model was established by ligating the sciatic nerve trunk with chromic catgut. In the CCI+ Tuina group, Tuina was applied at " Weizhong" (BL 20) on the operated side for 10 min each time, once a day for 14 days. The PWT and PWL of rats in each group were detected at baseline and Day 4, 10, 14 and 17 days after modeling. After intervention, the expression of IL-1β and IL-6 in the dorsal horn of the spinal cord were detected by ELISA, nissl staining was used to observe the morphology of neurons in the spinal dorsal horn. and the expression of c-Fos was detected by immunofluorescence staining.
Results Compared with the blank group, the PWT of the CCI group decreased on days 4, 10, 14 and 17 (t=27.52, 21.80, 14.36 and 16.23, all P<0.05). Compared with the CCI group, PWT in the CCI+ Tuina group increased on Days 10, 14 and 17 (t=-13.58, -6.83, -8.40, all P<0.05). Compared with the blank group, the PWL of the CCI group decreased on Days 4, 10, 14 and 17 (t=16.61, 27.22, 24.55 and 27.21, all P<0.05).Compared with the CCI group, PWL increased in the CCI+ Tuina group on Days 10, 14 and 17 (t=-9.35, 10.79, -21.86, all P<0.05).Compared with the blank group, the structure of neurons in the spinal dorsal hornon of the CCI group was damaged and the number of Nissl bodies reduced. Compared with the CCI group, the damage of neuronal structure in the spinal dorsal horn of the CCI+ Tuina group was improved, and Nissl bodies increased.Compared with the blank group, the expression of IL-1β and IL-6 in the spinal dorsal hornon of the CCI group increased (t=-13.97, 10.89, all P<0.05).Compared with the CCI group, the expression of IL-1β and IL-6 in the spinal dorsal horn decreased in the CCI+ Tuina group (t=2.98, 6.36, all P<0.05).Compared with the blank group, the expression of c-Fos in the spinal dorsal hornincreased in the CCI group (t=-7.97, P<0.05). Compared with the CCI group, the expression of c-Fos in thespinal dorsal horn decreased in the CCI+ Tuina group (t=7.14, P<0.05).
Conclusions Tuina at " Weizhong" (BL 20) can effectively increase PWT and PWL of CCI rats, improve the structure and morphology of neurons in the spinal dorsal horn, and alleviate NP. The mechanism may be related to reducing the expression levels of inflammatory factors such as IL-1β and IL-6, thereby inhibiting the activation of spinal dorsal horn neurons.