不同电压脉冲射频对CCI大鼠模型下丘脑β-内啡肽的影响

发布时间：2018-08-13 13:48

【摘要】：目的:观察不同电压脉冲射频(pulsed Radiofrequency,PRF)对慢性坐骨神经压迫损伤(chronic constriction injury of the sciatic nerve,CCI)大鼠模型下丘脑β-内啡肽含量的影响,探讨脉冲射频的镇痛机制。方法:雄性SD大鼠72只建立CCI疼痛模型后,随机分为4组(n=18):假刺激组H0、PRF低电压组H1(45v)、PRF中电压组H2(55v),PRF高电压组H3(65v)。PRF组:制模后7 d对其坐骨神经结扎近端行PRF,脉宽20ms,脉冲频率2 Hz,持续时间2 min,治疗电压分别为45v、55v、65v。假刺激组:制模7d后,在其相同位置放置射频电极,但无脉冲治疗,持续时间2min。制模前(T0)、制模后7 d(T1)、PRF后1(T2)、7(T3)和14 d(T4)测定大鼠疼痛行为学热痛阈(paw thermal withdrawal latency,PWTL)的变化。PRF后1、7和14 d,每组各处死6只大鼠,测定不同时间点大鼠下丘脑中β-内啡肽表达量及电镜观察神经微观结构变化。结果:PRF组在治疗后1、7和14d,与假刺激组比较,热痛阈均明显提高(P0.01)。其中术后第7d,中、高电压组热痛阈均明显高于低电压组,差异有统计学(P0.01);在实验结束时,与假刺激组对照,术后第1d,7d和14d,低、中、高电压组大鼠下丘脑β-内啡肽含量明显升高(P0.01);术后第7、14d,与低电压组相比,中、高组大鼠下丘脑β-内啡肽含量明显升高(P0.01);术后第14d,高电压组与中电压组差异显著(P0.05);在电镜观察下与假刺激组比较,经PRF干预后的坐骨神经损伤轻微。结论:1.电压45V、55V、65V的2Hz脉冲射频均可引起CCI大鼠热痛阈的升高,可能与其增加下丘脑β-内啡肽的含量有关。同时针尖温度波动小,推测不同电压的场强效应可能是PRF发挥镇痛作用的机理之一。2.PRF电压大于55V时,痛阈值降低没有进一步改善。然而β-内啡肽含量有所升高,可能会延长疼痛缓解的时间。
[Abstract]:Aim: to observe the effect of pulsed pulse radio frequency (pulsed) on the content of 尾 -endorphin in hypothalamus of rats with chronic sciatic nerve compression injury (chronic constriction injury of the sciatic nerveCCI), and to explore the analgesic mechanism of pulse radio frequency (PRF). Methods: 72 male Sprague-Dawley rats were used to establish CCI pain model. The rats were randomly divided into 4 groups (n / 18): sham stimulation group (H0), low voltage group (H _ 1 (45 v), medium voltage group H _ 2 (55 v) and high voltage group H _ 3 (65 v). PRF was performed on the proximal end of sciatic nerve ligation 7 days after modeling, pulse width was 20 Ms, pulse frequency was 2 Hz, duration was 2 min. Sham stimulation group: after 7 days, the radiofrequency electrode was placed in the same position, but there was no pulse therapy for 2 min. Before (T0), 1 (T2) 7 (T3) and 14 d (T4) after PRF, the changes of pain behavioral threshold (paw thermal withdrawal latencyPWTL were measured at 1 and 14 days after PRF. Six rats were killed in each group. The expression of 尾-endorphin in hypothalamus of rats was measured at different time points and the changes of nerve microstructure were observed by electron microscope. Results compared with the sham stimulation group, the thermal pain threshold of the 1: PRF group was significantly higher than that of the sham stimulation group on the 7th and 14th day after treatment (P0.01). The thermal pain threshold in the high voltage group was significantly higher than that in the low voltage group on the 7th day after operation (P0.01), and at the end of the experiment, compared with the sham stimulation group, it was lower and middle at the 1st day and 14th day after operation. The content of 尾 -endorphin in hypothalamus of rats in high voltage group was significantly higher than that in low voltage group (P0.01), and at the 7th day after operation, the content of 尾 -endorphin in hypothalamus was significantly higher than that in low-voltage group. The content of 尾 -endorphin in hypothalamus was significantly increased in high group (P0.01), the difference between high voltage group and medium voltage group was significant (P0.05) on the 14th day after operation. Compared with sham stimulation group under electron microscope, the sciatic nerve injury after PRF intervention was slight. Conclusion 1. The increase of thermal pain threshold in CCI rats could be attributed to the increase of 尾 -endorphin content in hypothalamus. At the same time, the temperature fluctuation of the needle tip is small. It is speculated that the field intensity effect of different voltage may be one of the mechanisms of analgesic effect of PRF. 2. When the voltage of PRF is greater than 55 V, the pain threshold is not further improved. However, increased beta-endorphin levels may prolong pain relief.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R402

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