AIM: To investigate the effect of stellate ganglion block (SGB) on nociception in Parkinson?s disease (PD) rat models, and to clarify the associated mechanism.

MATERIAL and METHODS: To generate PD nociception rat model 6-hydroxydopamine (6-OHDA) injection method was used. Paw withdrawal threshold (PWT) and paw retraction latency (PWL) was used to reflect mechanical stimulation and thermal stimulation, respectively, at pre-modeling and 1, 2, 3, 4 weeks post modeling. The preventive and therapeutic effects of SGB treatment on nociception were observed in Naive, Vehicle, and 6-OHDA group (model). Levels of IL-1?, IL-6, and TNF-? in striatum and periaqueductal gray (PAG) were detected with ELISA.

RESULTS: 6-OHDA injection induced obvious reduction of bilateral PWT from 2 to 4 weeks post modeling, suggesting that PD nociception rat model was successfully established. Continuous SGB prevention inhibited mechanical hyperalgesia at 2, 3 and 4 weeks post modeling, and significantly reversed mechanical hyperalgesia at 3 and 4 weeks post modeling, compared with those of Saline group (p<0.05). These results suggest that continuous SGB could effectively prevent and alleviate pain of PD rats. SGB treatment remarkably suppressed levels of inflammatory factors (IL-1 ?, IL-6, and TNF-?) in striatum and PAG of PD rats compared with those of rats in Vehicle group (p<0.05).

CONCLUSION: Continuous SGB effectively inhibited and reversed mechanical hyperalgesia of PD nociception rats through inhibiting inflammatory response in striatum and PAG.