电针对大鼠内脏痛结肠壁、背根节和脊髓内一氧化氮合酶的影响

目的:观察电针治疗内脏痛时结肠壁、背根神经节和脊髓内一氧化氮合酶(NOS)活性的变化,以探讨一氧化氮(NO)在痛觉传递中的作用及电针镇痛的机制。方法:26只SD大鼠随机分为正常对照组(6只)、内脏痛组(VP组,10只)和电针+内脏痛组(EA+VP组,10只)。电针取双侧“足三里”穴,运用NADPH-d酶组织化学技术和痛行为生理学方法,观察电针对福尔马林诱发大鼠盆腔内脏痛时,结肠壁、背根神经节和脊髓内NOS的影响。结果:内脏痛组大鼠在注射福尔马林后即出现明显的内脏痛行为表现,结肠、脊髓和背根节的NOS活性显著高于正常组(P<0.01);而电针+内脏痛组出现内脏痛行为表现时间推迟,腹痛表现减弱,NOS活性又显著低于内脏痛组(P<0.01)。结论:电针对大鼠急性盆腔内脏痛具有预防性治疗作用,NO可能参与电针对内脏痛的调节作用。

Effect of Electroacupuncture on the Activity of Nitric Oxide Synthase in the Colon, Dorsal Root Ganglia and Spinal Cord in Rats with Pelvic Pain

Objective: To study the effect of electroacupuncture(EA) on the activity of nitric oxide synthase(NOS) in the colon,dorsal root ganglia and spinal cord in rats with pelvic pain for studying the role of NO in pain transmission.Methods: Twenty-six SD rats were randomly divided into control group(n=6),model group(n=10) and EA group(n=10).EA(4-(6 Hz),dense-sparse waves,0.5-(3 V)) was applied to bilateral "Zusanli"(ST 36) for(60 min).Pelvic pain model was established by local injection of 5% formalin((40 μL)) to the colonic wall from the anus.Behavioral reactions were observed.After transcardiac perfusion of saline and paraformaldehyde,the rat's colon near the anus,sacral 2-4 ganglia and the corresponding spinal cord segments were removed to be cut into sections((25 μm)).NOS activity of the colon,dorsal root ganglia and spinal cord tissues was determined by using nicotinamide-adenine dinucleotide phosphate-diaphorase(NADPH-d) histochemistry.Results: In comparison with model group,the cumulative score of pain behavior in EA group was significantly lower(P<0.01).While the integral OD values of NOS of the colonic wall,DRG and spinal cord in model group were significant higher than those in control group(P<0.01).Comparison between model and EA groups showed that the integral OD values of NOS of the 3 types of tissues in EA group were markedly lower than those in model group(P<0.01),indicating that EA could suppress pelvic pain induced increase of NOS activity.Conclusion: EA can relieve formalin induced pelvic pain and suppress pain produced increase of NOS activity,suggesting NO may be involved in the process of EA analgesia.