鞘内注射右美托咪定对神经病理性疼痛大鼠DRG神经元GABA_A受体激活电流的影响
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摘要
目的:观察鞘内注射右美托咪定对神经病理性疼痛大鼠背根神经节(dorsal root ganglion, DRG)神经元GABA_A受体激活电流的影响。方法 :鞘内置管成功的雄性SD大鼠36只,体重180～220g,采用随机数字表法随机分为3组(n=12):假手术组(S组)、神经病理性疼痛组(CCI组)、右美托咪定+神经病理性疼痛组(D组)。S组和CCI组鞘内注射生理盐水每日10μl/次,D组鞘内注射右美托咪定2μg/kg,生理盐水稀释至10μl,每日1次,持续至术后14 d。各组于术前1 d (T0),术后3、5、7、10、14 d(T1-5)时测试热缩足潜伏期(thermal withdrawal latency, TWL)。于术后T5时测试完TWL后处死大鼠,在急性分离的DRG细胞上,运用全细胞膜片钳技术,记录不同浓度药物作用下各组背根神经节细胞GABA_A受体激活电流的变化。结果 :(1)与S组比较,CCI组和D组T1-5时TWL均缩短(P <0.05);与D组比较,CCI组T1-5时TWL均缩短(P <0.05)。(2)GABA (0.1～1000.0μmol/L)可以使85.7%(102/119)的DRG神经元产生浓度依赖性的内向电流,而且这种内向电流能被GABA_A受体选择性拮抗剂荷包牡丹碱(100μmol/L)所阻断。(3)CCI组在不同浓度(0.1～1000.0μmol/L) GABA激活电流幅值均小于S组和D组(P <0.05);D组在不同浓度(0.1～1000.0μmol/L) GABA激活电流幅度小于S组(P <0.05)。结论:右美托咪定通过增强GABA_A受体介导的突触前抑制作用,可能是其缓解神经病理性疼痛的机制之一。
Objective: To observe the effect of dexmedetomidine on GABA_A receptor-activated currents in dorsal root ganglion(DRG) neurons in rats with neuropathic pain. Methods: 36 male adult Sprague-Dawley rats, weighing(180-220 g), were randomly allocated into 3 groups(n =12): Sham group(S), chronic constrictive injury group(C), dexmedetomidine plus chronic constrictive injury group(D). D group intrathecal injection of dexmedetomidine 2 μg/kg evry day for 14 days, diluted with saline to 10 μl, while group S and group CCI received equal volumes of saline. Thermal withdrawal threshold(TWT) was assayed on 1 day before surgery, and 3, 5, 7, 10, 14 d after operation using radiant heat. The rats were sacrificed on 14 d(T5) after TWT tests. Whole cell patch clamp technique was used to record the effect of different concentrations of GABA on GABA_A receptor-activated currents in DRG neurons. Results:(1) Compared with group S, TWT values were reduced on T1-5in group CCI and D(P < 0.05); The TWT values were also reduced in group CCI as compared to group D.(2) GABA(0.1-1000.0 μmol/L) produced concentration-dependent inward current in 85.7% DRG neurons, and this kind of inward current could be blocked by bicuculline, a selective blocker for GABA_A receptors.(3) The currents of group CCI were decreased compared with group S and D(GABA, 0.1-1000.0 μmol/L). Contrast with group S, the currents of D decreased significantly(GABA, 0.1-1000.0 μmol/L). Conclusion: Dexmedetomidine potentiates the presynaptic inhibitory effect of GABA_A receptors, which may be one of its pharmacological mechanisms to relieve neuropathic pain in rats.
Objective: To observe the effect of dexmedetomidine on GABA_A receptor-activated currents in dorsal root ganglion(DRG) neurons in rats with neuropathic pain. Methods: 36 male adult Sprague-Dawley rats, weighing(180-220 g), were randomly allocated into 3 groups(n =12): Sham group(S), chronic constrictive injury group(C), dexmedetomidine plus chronic constrictive injury group(D). D group intrathecal injection of dexmedetomidine 2 μg/kg evry day for 14 days, diluted with saline to 10 μl, while group S and group CCI received equal volumes of saline. Thermal withdrawal threshold(TWT) was assayed on 1 day before surgery, and 3, 5, 7, 10, 14 d after operation using radiant heat. The rats were sacrificed on 14 d(T5) after TWT tests. Whole cell patch clamp technique was used to record the effect of different concentrations of GABA on GABA_A receptor-activated currents in DRG neurons. Results:(1) Compared with group S, TWT values were reduced on T1-5in group CCI and D(P < 0.05); The TWT values were also reduced in group CCI as compared to group D.(2) GABA(0.1-1000.0 μmol/L) produced concentration-dependent inward current in 85.7% DRG neurons, and this kind of inward current could be blocked by bicuculline, a selective blocker for GABA_A receptors.(3) The currents of group CCI were decreased compared with group S and D(GABA, 0.1-1000.0 μmol/L). Contrast with group S, the currents of D decreased significantly(GABA, 0.1-1000.0 μmol/L). Conclusion: Dexmedetomidine potentiates the presynaptic inhibitory effect of GABA_A receptors, which may be one of its pharmacological mechanisms to relieve neuropathic pain in rats.
引文
[1]伟东,陈彦青.右美托咪定及舒芬太尼联合鞘内注射对CCI模型大鼠的镇痛效应[J].中国疼痛医学杂志, 2013, 19(5):336-340.
[2]姚敏,张兆平,房宁宁,等.关节腔内给予右美托咪定对膝关节镜术后镇痛的影响[J].临床麻醉学杂志,2012, 28:896-898.
[3]王缠生.轻度子痫前期产妇剖宫产40例鞘内注射右美托咪定的效果观察[J].贵阳中医学院学报, 2013,35:139-140.
[4]Mikami M, Zhang Y, Kim B, et al. Dexmedetomidine's inhibitory effects on acetylcholine release from cholinergic nerves in guinea pig trachea:a mechanism that accounts for its clinical benefit during airway irritation[J].Bmc Anesthesiology, 2017, 17:52.
[5]HoKM,IsmailH.Useofintrathecalmidazolamto improveperioperativeanalgesia:ameta-analysis[J].Anaesth Intensive Care, 2008, 36:365-373.
[6]Ma KT, Si JQ, Zhang ZQ, et al. Modulatory effect of CCK-8SonGABA-induceddepolarizationfromrat dorsal root ganglion[J]. Brain research, 2006, 1121:66-75.
[7]SiJQ,ZhangZQ,LiCX, etal.Modulatoryeffectof substance P on GABA-Activated currents from rat dorsal root ganglion[J]. Acta Pharmacol Sin, 2004, 25:324-328.
[8]Lu C, Fang Ye, Que HL, et al. Increased Hyperalgesia andProinflammatoryCytokinesintheSpinalCord andDorsalRootGanglion AfterSurgeryand/orFentanyl AdministrationinRats[J]. Anesth Analg,2018,126:289-297.
[9]杨建平,蒋豪,吴钰.大鼠蛛网膜下腔埋管并长期留置操作的改进[J].中华麻醉学杂志, 1993, 13:110-112.
[10]朱贺,马克涛,李丽,等.神经病理性疼痛大鼠DRG神经元GABAA受体激活电流的变化[J].中国应用生理学杂志, 2011, 27:376-379.
[11]Li L, Zhao L, Wang Y, et al. PKC?mediates substance P inhibition of GABAA receptors-mediated current in rat dorsal root ganglion[J].华中科技大学学报(医学英德文版), 2015, 35:1-9.
[12]樊超,马克涛,杨越,等.咪达唑仑对大鼠背根神经节神经元GABAA受体激活电流的影响[J].中华麻醉学杂志, 2012, 32:1104-1107.
[13]梁伟东,陈彦青.右美托咪定及舒芬太尼联合鞘内注射对CCI模型大鼠的镇痛效应[J].中国疼痛医学杂志, 2013, 19(5):336-340.
[14]BrandonNJ,DelmasP,KittlerJT, etal.GABAAreceptorPhosphorylationandfunctionalmodulationin corticalneurons by a protein kinase c-dependent pathway[J]. J Biol Chem, 2000, 275:38856-38862.
[15]De LE, Ravasenga T, Petrini EM, et al. Inter-Synaptic Lateral Diffusion of GABAA Receptors Shapes Inhibitory Synaptic Currents[J]. Neuron, 2017, 95:63-69.
[16]樊超,马克涛,杨越,等.咪达唑仑对神经病理性疼痛大鼠DRG神经元GABAA受体激活电流的增强作用[J].中国疼痛医学杂志, 2013, 19(5):330-335.
[17]Asiedu MN, Meiia G, Ossipov MK, et al. Modulation ofspinalGABAergicanalgesiabyinhibitionofchlocide extrusion capacity in mice[J]. J pain, 2012, 13:546-554.
[18]Naik AK, Pathirathna S, Jevtovic-Todorovic V. GABAA receptor modulation in dorsal root ganglia in vivo affects chronic pain after nerve injury[J]. Neuroscience,2008, 154:1539-1553.
[19]Yamakita S, Matsuda M, Yamaguchi Y, et al. Dexmedetomidine prolongs levobupivacaine analgesia via inhibition of inflammation and p38 MAPK phosphorylation inratdorsalrootganglion[J].Neuroscience,2017,361:58-68.
[2]姚敏,张兆平,房宁宁,等.关节腔内给予右美托咪定对膝关节镜术后镇痛的影响[J].临床麻醉学杂志,2012, 28:896-898.
[3]王缠生.轻度子痫前期产妇剖宫产40例鞘内注射右美托咪定的效果观察[J].贵阳中医学院学报, 2013,35:139-140.
[4]Mikami M, Zhang Y, Kim B, et al. Dexmedetomidine's inhibitory effects on acetylcholine release from cholinergic nerves in guinea pig trachea:a mechanism that accounts for its clinical benefit during airway irritation[J].Bmc Anesthesiology, 2017, 17:52.
[5]HoKM,IsmailH.Useofintrathecalmidazolamto improveperioperativeanalgesia:ameta-analysis[J].Anaesth Intensive Care, 2008, 36:365-373.
[6]Ma KT, Si JQ, Zhang ZQ, et al. Modulatory effect of CCK-8SonGABA-induceddepolarizationfromrat dorsal root ganglion[J]. Brain research, 2006, 1121:66-75.
[7]SiJQ,ZhangZQ,LiCX, etal.Modulatoryeffectof substance P on GABA-Activated currents from rat dorsal root ganglion[J]. Acta Pharmacol Sin, 2004, 25:324-328.
[8]Lu C, Fang Ye, Que HL, et al. Increased Hyperalgesia andProinflammatoryCytokinesintheSpinalCord andDorsalRootGanglion AfterSurgeryand/orFentanyl AdministrationinRats[J]. Anesth Analg,2018,126:289-297.
[9]杨建平,蒋豪,吴钰.大鼠蛛网膜下腔埋管并长期留置操作的改进[J].中华麻醉学杂志, 1993, 13:110-112.
[10]朱贺,马克涛,李丽,等.神经病理性疼痛大鼠DRG神经元GABAA受体激活电流的变化[J].中国应用生理学杂志, 2011, 27:376-379.
[11]Li L, Zhao L, Wang Y, et al. PKC?mediates substance P inhibition of GABAA receptors-mediated current in rat dorsal root ganglion[J].华中科技大学学报(医学英德文版), 2015, 35:1-9.
[12]樊超,马克涛,杨越,等.咪达唑仑对大鼠背根神经节神经元GABAA受体激活电流的影响[J].中华麻醉学杂志, 2012, 32:1104-1107.
[13]梁伟东,陈彦青.右美托咪定及舒芬太尼联合鞘内注射对CCI模型大鼠的镇痛效应[J].中国疼痛医学杂志, 2013, 19(5):336-340.
[14]BrandonNJ,DelmasP,KittlerJT, etal.GABAAreceptorPhosphorylationandfunctionalmodulationin corticalneurons by a protein kinase c-dependent pathway[J]. J Biol Chem, 2000, 275:38856-38862.
[15]De LE, Ravasenga T, Petrini EM, et al. Inter-Synaptic Lateral Diffusion of GABAA Receptors Shapes Inhibitory Synaptic Currents[J]. Neuron, 2017, 95:63-69.
[16]樊超,马克涛,杨越,等.咪达唑仑对神经病理性疼痛大鼠DRG神经元GABAA受体激活电流的增强作用[J].中国疼痛医学杂志, 2013, 19(5):330-335.
[17]Asiedu MN, Meiia G, Ossipov MK, et al. Modulation ofspinalGABAergicanalgesiabyinhibitionofchlocide extrusion capacity in mice[J]. J pain, 2012, 13:546-554.
[18]Naik AK, Pathirathna S, Jevtovic-Todorovic V. GABAA receptor modulation in dorsal root ganglia in vivo affects chronic pain after nerve injury[J]. Neuroscience,2008, 154:1539-1553.
[19]Yamakita S, Matsuda M, Yamaguchi Y, et al. Dexmedetomidine prolongs levobupivacaine analgesia via inhibition of inflammation and p38 MAPK phosphorylation inratdorsalrootganglion[J].Neuroscience,2017,361:58-68.