鞘内注射不同浓度蛋白激酶B抑制剂Ⅳ对瑞芬太尼痛觉过敏的影响

摘要

Objective To investigate the role and mechanism of protein kinase B (Akt) in opioid-induced hyperalgesia (OIH) with an incisional pain model.Methods Sixty C57BL/6 male mice were randomly divided into 5 groups (n=12):incision pain+ dimethyl sulfoxide(DMSO) group(group Ⅰ),incision pain+remifentanil+DMSO group(group R),Akt inhibitor Ⅳ 0.08 μg/10 μl group(group A1),Akt inhibitor Ⅳ 0.16 μg/10 μl group(group A2) and Akt inhibitor Ⅳ 0.32 μg/10 μl group(group A3).DMSO was the solvent of Akt inhibitor Ⅳ.Incisional pain model was made in the right paw of all the mice.In group R and group A1,A2,A3,subcutaneous remifentanil(0.04 mg/kg) was infused for 30 min while the surgery was being performed and intrathecal 10 μl DMSO(10％) with corresponding concentration of the Akt inhibitor Ⅳ 10 μl was injected respectively.The paw mechanical withdrawal threshold (PMWT) and the paw withdrawal thermal latency(PWTL) was tested at 1 d(T0) before and 6 h(T1),1(T2),2(T3),3(T4),5(T5),7 d(T6) after surgery.Results Compared with group Ⅰ and the baseline value,PMWT and PWTL were significantly decreased after surgery except 7 d in group R and all group A(P＜0.05).Compared with group R,PMWT[(5.03±0.62),(6.10±0.86),(5.92±0.88),(6.01±1.02) g.(4.07±0.79),(4.73±0.48),(4.77±0.59),(4.86±0.56) g.(5.05±0.75),(5.99±0.63),(5.99±0.71),(6.00±0.81) g] and PWTL[(0.48±0.06),(0.60±0.08),(0.61±0.07),(0.58±0.04) s.(0.38±0.07),(0.50±0.08),(0.48±0.06),(0.45±0.08) s.(0.37±0.09),(0.52±0.09),(0.49±0.12),(0.58±0.21) s] were significantly increased after surgery except 7 d in groups A1,A2,A3 (P＜0.05).While there was no significant difference among group A1,A2 and A3 (P＞0.05).Conclusions Intrathecal injection of different doses of Akt inhibitor Ⅳ effectively alleviates hyperalgesia induced by remifentanil in non-dose-dependent way.%目的 通过观察鞘内注射不同浓度的蛋白激酶B(protein kinase B,Akt)抑制剂Ⅳ对切口痛瑞芬太尼痛觉过敏小鼠痛行为学的影响,初步探讨Akt在阿片诱导的痛觉过敏(opioid-induced hyperalgesia,OIH)中的作用及其机制. 方法 C57BI/6小鼠60只,采用随机数字表法分为5组(每组12只):切口痛+二甲基亚砜(dimethyl sulfoxide,DMSO)组(Ⅰ组)、瑞芬太尼+DMSO组(R组)、Akt抑制剂Ⅳ0.08 μg/10μl组(A1组)、Akt抑制剂Ⅳ0.16 μg/10μl组(A2组)、Akt抑制剂Ⅳ0.32 μg/10μl组(A3组),其中DMSO是Akt抑制剂Ⅳ的溶媒.所有分组均在右侧足做切口痛,R组、A1组、A2组及A3组造模同时腹部皮下泵注瑞芬太尼(0.04 mg/kg)30 min.R组及A1组、A2组及A3组术前30 min分别鞘内给予10％ DMSO 10μl和相应浓度的Akt抑制剂Ⅳ10μl.各组小鼠在术前1 d(T0)及术后6 h(T1)、1(T2)、2(T3)、3(T4)、5(T5)、7 d(T6)检测术侧后足热缩足潜伏期(paw withdrawal thermal latency,PWTL)及机械缩足阈值(paw mechanical withdrawal threshold,PMWT). 结果 与Ⅰ组和基础值比较,R组、A1组、A2组及A3组术后各时间除术后7d外PMWT和PWTL均降低(P＜0.05);与R组比较,A1组、A2组及A3组术后6h、1、2d的PMWT [(5.03±0.62)、(6.10±0.86)、(5.92±0.88)、(6.01±1.02) g;(4.07±0.79)、(4.73±0.48)、(4.77±0.59)、(4.86±0.56)g;(5.05±0.75)、(5.99±0.63)、(5.99±0.71)、(6.00±0.81)g]和术后1、2、3d的PWTL明显升高[(0.48±0.06)、(0.60±0.08)、(0.61±0.07)、(0.58±0.04)s;(0.38±0.07)、(0.50±0.08)、(0.48±0.06)、(0.45±0.08) s;(0.37±0.09)、(0.52±0.09)、(0.49±0.12)、(0.58±0.21)s](P＜0.05);A1组、A2组及A3组的各时间点的PWMT和PWTL差异无统计学意义(P＞0.05); 结论 预先鞘内注射Akt抑制剂Ⅳ能够有效缓解瑞芬太尼诱发的痛觉过敏,而且没有剂量依赖性.