"足三里"和"肾俞"穴位埋线对大鼠吗啡镇痛耐受和运动行为敏化的影响

目的:观察"足三里"和"肾俞"穴位埋线对大鼠吗啡镇痛耐受和行为敏化的效应差异,探讨其作用机制.方法:大鼠随机分为模型组、非穴位点组、肾俞组、足三里组.除模型组外,其余3组均于注射吗啡10 d前开始行穴位埋线.建立慢性吗啡耐受模型,每天应用热板试验测定痛阈.并在第1次吗啡注射,以及吗啡停药1 w后再激发进行活动度检测.应用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶(NADPH-d)组织化学显示一氧化氮合酶阳性神经元.结果:与非穴位点组相比,"足三里"埋线减缓慢性吗啡处理的痛阁下降和减少大鼠活动度,伏隔核和背侧纹状体内一氧化氮合酶阳性神经元表达减少;肾俞组痛阈和活动度较非穴位点组均未见明显差异,而背侧纹状体区一氧化氮合酶阳性神经元表达明显减少.结论:穴位埋线于"足三里"可减缓吗啡镇痛耐受,逆转吗啡行为敏化形成,其调节可能与抑制伏隔核和背侧纹状体区一氧化氮合酶表达有关.

Effects of catgut embedding at "Zusanli" (ST 36) and "Shenshu" (BL 23) on Morphine analgesic tolerance and locomotor sensitization in the rat

OBJECTIVE: To compare effects of catgut embedding at "Zusanli" (ST 36) and "Shenshu" (BL 23) on Morphine analgesic tolerance and locomotor sensitization induced by chronic Morphine administration and the mechanism. METHODS: The rats were randomly divided into a model group, a non-acupoint group, a Shenshu group and a Zusanli group. The rats, except those in the model group, were pretreated with acupoint catgut-embedding 10 days before the first Morphine injection. The Morphine-tolerance model was established and the pain threshold was detected by hot-plate test every day. Locomotor activities were recorded after the first Morphine injection and Morphine-challenging 1 week after withdrawal of Morphine. The positive neurons of nitric oxide synthetase (NOS) were showed by NADPH-d histochemical method. RESULTS: Compared with the non-acupoint group, catgut embedding at "Zusanli" (ST 36) could attenuate the Morphine analgesic tolerance and the increase of locomotor activities in rats. Meanwhile, the expression of NOS positive neurons in nucleus accumbens septi and dorsal striatum decreased in the Zusanli group. There were no significant differences between the Shenshu group and the non-acupoint group in the analgesic threshold and locomotor sensitization, but the expression of NOS positive neurons in the striatum region significantly decreased. CONCLUSION: Catgut embedding at "Zusanli" (ST 36) can attenuate Morphine analgesic tolerance and reverse formation of locomotion sensitization induced by chronic Morphine administration, which are possibly related with inhibition of the expression of NOS positive neurons in nucleus accumbens septi and dorsal striatum.