不同压力高压氧治疗对大鼠神经病理性痛的影响

Effect of different pressures of hyperbaric oxygen treatment on neuropathic pain in rats

目的探讨不同压力高压氧治疗（HBO）对大鼠神经病理性痛的影响。方法成年雄性SD大鼠24只，采用随机数字表法，将其分为4组（n=6）：假手术组（S组）、神经病理性痛组（NP组）、2．0标准大气压高压氧治疗组（HBO2.0组）、2．5标准大气压高压氧治疗组（HBO2.5组）。将HBO2.0组和HBO2.5,组大鼠置于高压氧舱，以10kPa／min的速率向舱内匀速加压直至目标压力并保持60min。然后以10kPa／min的速率匀速减压至正常大气压。从术后1d开始高压氧治疗，连续5d，1次／d。S组和NP组单纯放入氧舱100min而不接受治疗。于出高压氧舱后即刻（T0）、1h（T1）和2h（T2）时测定机械缩足反应阈（MWT）和热缩足反应潜伏期（TWL）。结果与S组比较，NP组MWT降低，TWL缩短（P〈0．05）。与NP组比较，HBO2.0组和HBO2.5组高压氧治疗期间T1时MWT升高，TWL延长（P〈0．05），T2时MWT和TWL差异无统计学意义（P〉0．05）。HBO2.0组和HBO2.5 组间各时点MWT和TWL比较差异无统计学意义（P〈0．05）。结论不同压力高压氧治疗均可减轻大鼠神经病理性痛，但压力改变不影响镇痛效果。

Objective To investigate the effect of different pressures of hyperbaric oxygen （HBO） treat- ment on neuropathic pain （NP） in rats. Methods Twenty-four healthy male Sprague-Dawley rats were randomly divided into 4 groups （ n = 6 each） ： sham operation group （group S）, NP group,treatment with HBO at 2.0 atmo- sphere absolute group （group HBO2.0 ） and treatment with HBO at 2.5 atmosphere absolute group （group HBO2.5 ） . The animals were anesthetized with intraperitoneal 5 % chloral hydrate 300 mg/kg. NP was induced by chronic con- strictive injury. The left sciatic nerve was exposed and 4 loose ligatures were placed on the sciatic nerve at 1-mm intervals with 4-0 silk thread. After the rats were placed in the HBO chamber, the pressure was increased at a rate of 10 kPa/min until the desired pressure was reached, and then the pressure was maintained at this level for 60 min. The pressure was then decreased at a rate of 10 kPa/min until the normal pressure was reached. HBO treat- ment was performed Once a day for 5 consecutive days starting from I st day after operation in groups HBO2.0 and HBO2.5 . While the rats were only placed in the HBO chamber and stayed for 100 min in groups S and NP. The mechanical paw withdrawal threshold （MWT） and thermal paw withdrawal latency （TWL） were measured at 0, 1 and 2 h after leaving the HBO chamber （T0-2）. Results Compared with group S, MWT was significantly de- creased and TWL was shortened in group NP （ P 〈 0.05）. Compared with group NP, MWT was significantly in- creased and TWL prolonged at T1 during the treatment （ P 〈 0.05）, while no significant change was found in MWT and TWL at T2 during the treatment in groups HBO2.0 and HBO2.5 （ P 〉 0.05）. There was no significant differencein MWT and TWL at each time point during the treatment between groups HBO2.0 and HBO2.5 （P 〉 0.05）. Con- clusion Treatment with different pressures of HBO can reduce NP in rats, but the change in pressure dose not af- fect the analgesic efficacy.