Abstract: Objective  To observe the effect of early use of 0.25 MPa hyperbaric oxygen (HBO) on pain behavior in model rat of neuropathic pain (NP) and explore the mechanism.  Methods  Fifty-four male Sprague-Dawley (SD) rats were randomly divided into 3 groups (18 rats per group) including sham operation, sciatic nerve ligation with chronic constriction injury (CCI) and HBO early-treatment groups. The rat model of neuropathic pain was established, and CCI + HBO group received 0.25 MPa HBO treatment for 60 min per day at early stage, continuing for 5 d. The changes in general state of health, the number of paw withdrawal responses, paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were assessed at different time points after operation.  Results  Compared with sham-operated group, the body weight of rats in CCI group decreased significantly (t = 4.772, P = 0.000) on the 14th day; the body weight of rats in CCI + HBO group was significantly higher than that in CCI group (t = 2.411, P = 0.029). Compared with sham-operated group, reduced PWL immediately after operation (t = 28.345, P = 0.000), and more paw withdrawal responses (t = 12.541, P = 0.000) and decreased PWT (t = 4.032, P = 0.001) from the 3rd day after operation were observed in CCI group. Compared with CCI group, the number of paw withdrawal responses decreased (t = 8.077, P = 0.000), and PWT and PWL increased (t = 2.114, P = 0.049; t = 7.715, P = 0.000) in CCI + HBO group.  Conclusion  0.25 MPa HBO treatment at early stage can ameliorate the mechanical and thermal hyperalgesia. HBO may provide a new convenient and effective way for the treatment of neuropathic pain in clinic.

Key words: Neuralgia, Wounds and injuries, Sciatic nerve, Hyperbaric oxygenation, Disease modals, animal

摘要： 目的 观察神经病理性疼痛发病早期0.25 MPa 高压氧治疗对大鼠疼痛行为学的影响，并探讨早期治疗的作用机制。方法 采用左后肢坐骨神经结扎术建立慢性压迫性损伤大鼠模型，术后早期（第1 天）即开始进行高压氧（0.25 MPa）治疗（60 min/d），5 d 后观察大鼠一般情况、自发缩足次数、缩足阈值（PWT）和缩足潜伏期（PWL）等疼痛行为学变化。结果 与假手术组相比，模型组大鼠体质量显著下降（t = 4.772，P = 0.000）、高压氧组大鼠体质量降低幅度小于模型组（t = 2.411，P = 0.029）；模型组大鼠术后即出现缩足潜伏期缩短（t = 28.345，P = 0.000），第3天开始自发缩足次数增多（t = 12.541，P = 0.000）、缩足阈值降低（t = 4.032，P = 0.001）。与模型组相比，高压氧治疗组大鼠术后第3 天开始缩足次数减少（t = 8.077，P = 0.000）、缩足阈值增加（t = 2.114，P = 0.049）、缩足潜伏期延长（t = 7.715，P = 0.000）。结论 早期施行高压氧（0.25 MPa）治疗可以显著改善神经病理性疼痛大鼠痛敏症状，为临床神经病理性疼痛提供一种新的便捷、经济、有效的治疗方法。

关键词: 神经痛, 创伤和损伤, 坐骨神经, 高压氧, 疾病模型, 动物