中枢敏化和外周敏化在瑞芬太尼诱发炎性痛大鼠痛觉过敏中的作用

Role of central and peripheral sensitization in remifentanii-induced hyperalgesia in a rat model of inflammatory pain

目的 探讨中枢敏化和和外周敏化在瑞芬太尼诱发炎性痛大鼠痛觉过敏中的作用。方法雄性SD大鼠21只，体重200～300g，采用随机数字表法，将其随机分为3组（n=7）：生理盐水对照组（c组）、低剂量瑞芬太尼组（R。组）和高剂量瑞芬太尼组（R2组），3组均采用左侧跖底皮下注射1％角叉菜胶100脚的方法制备大鼠炎性痛模型。R1组和R组于造模前5min至造模后25min分别静脉输注瑞芬太尼10、30μg·kg^-1·min^-1，C组给予等容量生理盐水。分别于造模前、造模后1h、3h、1-7d时测定双侧机械缩足阈值（PWT）；分别于造模前、造模后2h、4h、1～7d时测定双侧热刺激缩足潜伏期（PWL）；分别于造模前、造模后1h,4h、1～7d时测定左侧后爪跖底的厚度。结果与C组比较，R1组和R2组在造模后1d时双侧邢汀降低（P〈0．05）；与R1组比较，R1组在造模后2,4—7d时右侧PWT降低（P〈0．05）；3组间双侧PWL和左侧后爪跖底厚度比较差异无统计学意义（P〉0．05）。结论中枢敏化参与了瑞芬太尼诱发炎性痛大鼠痛觉过敏的发生和维持，而外周敏化未参与。

Objective To investigate the role of central and peripheral sensitization in remifentanil-induced hyperalgesia in a rat model of inflammatory pain. Methods Twenty-one male SD rats weighing 200-300 g were used in this study. Inflammatory pain was induced by intraplantar injection of 1% carrageenan 100μl in the left hindpaw in all animals. The animals were then randomly divided into 3 groups （ n = 7 each） ： control group （group C） and two remifentanil groups （group R1 , R2 ）. In RI and R2 groups remifentanil was infused iv at a rate of 10 and 30 μg·kg^-1·min^-1 respectively starting from 5 min before till 25 min after carrageenan injection, while in group C normal saline was infused iv instead of remifentanil. Bilateral paw withdrawal threshold to mechanical stimulation with yon Frey filament （PWT） was measured before （baseline） and at 1 h, 3 h and 1-7 d after carrageenan injection. Bilateral paw withdrawal latency to noxious thermal stimuli （PWL） was measured before and at 2 h, 4 h and 1-7 d after carrageenan injection. The thickness of the plantar surface of left hindpaw was measured before and at 1 h, 4 h and 1-7 d after carrageenan injection. Results Bilateral PWT was significantly lower at day 1 after carrageenan injection in RI and R1 groups than in group C. The right PWT was significantly lower at 2 d and 4-7 d after carrageenan injection in group R2 than in group R1 . There was no significant difference in PWL and thickness of the plantar surface of left hindpaw among the 3 groups. Conclusion Central sensitization is involved in developing and maintaining the remifentanil-induced hyperalgesia in a rat model of inflammatory pain, while peripheral sensitization is not.