鞘内注射加巴喷丁对切口痛大鼠吗啡镇痛效应的影响

目的 探讨鞘内注射加巴喷丁对切口痛大鼠吗啡镇痛效应的影响.方法 雄性SD大鼠,体重250g～280 g,取鞘内置管成功的大鼠48只,随机分为6组(n=8):假手术组(S组)鞘内注射人工脑脊液(ACSF)10μl后,吸人1.4%异氟烷5 min,不制备模型;切口痛组(IP组)、加巴喷丁50μg组(G组)、吗啡2.5μg组(M1组)和吗啡5μg组(M2组)于制备切口痛模型前30 min分别鞘内注射ACSF10μl、加巴喷丁50μg、吗啡2.5μg和5μg;加巴喷丁50μg+吗啡2.5μg组(G+M1组)于制备模型前30 min鞘内注射加巴喷丁50μg和吗啡2.5μg.模型制备后2 h时测定术侧机械缩爪反射阈值(MWT)和热刺激缩爪反应潜伏期(TWL).结果 与S组比较,IP组、G组、M1组MWT降低,TWL缩短(P＜0.05),G+M1组和M2组MWT和TWL差异无统计学意义(P＞0.05);与IP组比较,G+M1组和M2组大鼠MWT升高,TWL延长(P＜0.05),G组和M1组MWT和TWL差异无统计学意义(P＞0.05);与G+M1组比较,G组和M1组MWT降低,TWL缩短(P＜0.05).结论 鞘内注射加巴喷丁可增强吗啡对切口痛大鼠的镇痛效应.

Effects of intrathecal gabapentin on analgesic efficacy of morphine in a rat model of incisional pain

Objective To investigate the effects of intrathecal (IT) gabapentin on the analgesic efficacy of morphine in a rat model of incisional pain. Methods Forty-eight male SD rats in which IT catheters were successly inserted according to the method described by Yaksh were randomly divided into 6 groups ( n = 8 each): Ⅰ sham operation group, Ⅱ incisional pain group, Ⅲ GBP 50 μg group, Ⅳ morphine 2.5 μg group, Ⅴ morphine 5 μg group, and Ⅵ morphine 2.5 μg + gabapentin 50 μg group. In group Ⅰ , IT artificial cerebrospinal fluid (ACSF)10 μl was injected and then 1.4% isoflurane was inhaled for 5 min. IT ACSF 10 μl, gabapentin 50μg and morphine 2.5 and 5 μg were injected 30 min before the establishement of the model in group Ⅱ -Ⅴ respectively. Paw withdrawl threshold (PWT) to mechanical stimulation and paw withdrawal latency (PWL) to a thermal nociceptive stimulus were measured at 2 h after the establishement of the model. Results Compared with group Ⅰ , MWT was significantly decreased and TWL was significantly shortened in group Ⅱ , Ⅲ and Ⅳ ( P ＜ 0.05), but no significant change in MWT and TWL was found in group Ⅴ and Ⅵ (P＞0.05). Compared with group Ⅱ , MWT was significantly increased and TWL was significantly prolonged in group Ⅴ and Ⅵ (P ＜ 0.05), but no significant change in MWT and TWL was found in group Ⅲ and Ⅳ/ ( P ＞ 0.05). MWT was significantly decreased and TWL was significantly shortened in group Ⅲ and Ⅳ compared with group Ⅵ ( P ＜ 0.05). Conclusion IT gabapentin enhances the analgesic efficacy of morphine in a rat model of incisional pain.