电针对SNI大鼠痛觉过敏及脊髓背角NOS阳性神经元表达的影响

Effect of Electroacupuncture on Hyperalgesia and NOS Positive Neurons Expression in Dorsal Horns of Spinal Cord in Rats with Spared Nerve Injury

目的:探讨电针对SNI大鼠痛觉过敏及脊髓背角NOS阳性神经元表达的影响。方法:SD大鼠随机分为假手术组、模型组和电针组(n=8)。采用坐骨神经分支选择性损伤模型,电针"委中"和"环跳"穴,观察其对大鼠机械痛阈和热痛阈的影响,以还原型尼克酰胺腺嘌呤二核苷酸脱氢酶(NADPH-d)法,观察各组大鼠脊髓背角NOS阳性神经元的变化,并用平均光密度来定量表示脊髓背角NOS的阳性神经元表达。结果:SNI手术可显著降低大鼠机械痛阈,损伤侧脊髓背角NOS阳性神经元表达显著升高,与假手术组及非伤侧相比,差异均有显著性(P<0.05或0.01);电针干预后大鼠伤侧脊髓背角的NOS阳性神经元表达降低,与模型组比较差异有显著性(P<0.05),与此同时大鼠机械痛敏状态显著改善,甚至痛行为消失。结论:电针减轻神经病理性痛的痛过敏可能与其调控脊髓NOS的功能有关。

Objective：To investigate the effect of electroacupuncture（EA） on hyperalgesia and NOS positive neurons expression in dorsal horns of spinal cord in rats with spared nerve injury（SNI）.Methods：SD rats were randomly divided into sham-opration（SO） group,model（M） group and electroacupuncture（E） group（both n=8）.Spared nerve injury（SNI） model was adopted,in the E group EA（2Hz,onset 1mA,enhance 1mA each 10 minutes） was applied to ＂Wei zhong＂（BL 40） and ＂Huan tiao＂（GB 30） for 30 minutes to observe the mechanical pain threshold and thermal pain threshold in rats.Observe the changes of NOS in spinal cord dorsal horns of rats in each group and quantified its＇expression with average optical density by nicotinamide adenine dinucleotide phosphate enzyme（NADPH-d） method.Results：After the SNI opration the mechnical pain threshold in rats were decreased significantly,but the expression of NOS in injured-side of spinal cord dorsal horns in M group was increased makedly compared to SO group and it＇s non-injured side（P0.05,0.01）.After electroacupuncture the expression of NOS in injured-side of spinal cord dorsal horns in E group was decreased makedly compared to M group（P0.05）,simultaneously,the mechanical hyperalgesia state in E group alleviated significantly compared to that of M group,also the pain behavior improved distinctly or even disappeared.Conclusion：It is suggested that EA analgesia mechanism may be related to regulation the function of NOS in spinal cord.