加巴喷丁治疗神经病理性疼痛的疗效分析

Efficacy of gabapentin in the management of neuropathic pain

目的:探讨加巴喷丁(GBP)治疗神经病理性疼痛的疗效。方法:将雄性SD大鼠30只随机分为5组(n=6),假手术对照组(SC组)、疼痛模型对照组(PC组)、小剂量GBP治疗组(S组)、中剂量GBP治疗组(M组)和大剂量GBP治疗组(L组)。除SC组外,各组均行左侧腰5神经结扎术(SNL)制作神经病理性疼痛模型,术后第1天开始分别给予生理盐水(SC组、PC组)或GBP50(S组)、100(M组)、200(L组)mg/(kg·d),直至第15天。手术前1d,手术后1、3、5、7、9、11、13、15d分别进行机械性痛敏和热痛敏实验,记录后肢机械触痛阈值(PWPT)和回缩潜伏期(PWL)。结果:与术前基础值和SC组比较,PC组SNL后从第1天起左后肢PWPT下降,PWL缩短,以术后第5天最显著,差异有显著性(P<0.01)。与PC组比较,GBP灌胃治疗后,各组左后肢PWPT上升,PWL延长,S组、M组和L组PWPT分别于术后11、9和7d起差异有显著性(P<0.05或P<0.01),PWL分别于术后13、11和9d起差异有显著性(P<0.05或P<0.01),并维持至术后15d。与S组比较,L组左后肢PWPT上升,于术后15d差异有显著性(P<0.05)。结论:50mg/(kg·d)的GBP可显著增加大鼠神经病理性疼痛的机械痛阈和热痛阈,100mg/(kg·d)和200mg/(kg·d)的作用更加明显。

Objective To explore the efficacy of gabapentin （GBP） in the management of neuropathic pain induced by spinal nerve ligation （SNL）. Methods Thirty male Sprague-Dawley rats were randomly divided into 5 groups （n = 6）： sham operation control group （group SC）, neuropathic pain control group （group PC）, low-dose GBP group [group S, 50 mg/（kg·d）], moderate-dose GBP group [group M, 100 mg/（kg·d）] and high-dose GBP group [group L, 200 mg/（kg·d）]. The neuropathic pain model was constructed via ligating left L5 spinal nerve. After operation the rats in group SC and group PC received an intragastric administration of normal saline and the rats in 3 treatment group respectively received an intragastric administration of GBP at 3 different doses from the first day to the fifteenth day. As indicators of mechanical and heat hyperalgesia, paw withdrawal pressure threshold （PWPT） and paw withdrawal latency （PWL） were measured one day before and 1, 3, 5, 7, 9, 11, 13, and 15 days after SNL. Results PWPT and PWL of the left hind paw in group PC declined on day 1 and reached to the lowest level on day 5 after SNL as compared with baseline and those in group SC （P 〈 0.01）. PWPT and PWL of the left hind paw were markedly higher in groups S, M, and L than in group PC. There was a significant difference in PWPT between group S and group PC on day 11, between group M and group PC on day 9, and between group L and group PC on day 7 （P 〈 0.05 or P 〈 0.01）. PWL differed markedly between group S and group PC on day 13, between group M and group PC on day 11, and between group L and group PC on day 9 （P 〈 0.05 or P 〈 0.01 ）. A significant difference in PWPT of left hind paw between group L and group S occurred on day 15 （P 〈 0.05）. Conclusion GBP of 50 mg/（kg·d） can evidently elevate the mechanical and thermal pain threshold of neuropathic pain in rats and this analgetic effect is more obvious with a twofold or fourfold increase in dosage.