脊髓中P物质参与电针镇痛的研究

Study on a Role of Substance P in the Spinal Mechanisms of Electroacupuncture Analgesia

本研究发现，低频（２Ｈｚ）电针刺激时大鼠脊髓中Ｐ物质免疫活性（ＳＰ－ｉｒ）含量减少，中频（１５Ｈｚ）、高频（１００Ｈｚ）和变频（２／１５Ｈｚ）刺激时ＳＰ－ｉｒ含量增多。脊髓蛛网膜下腔（ｉ．ｔ．）注射非肽类ＳＰ（ＮＫＩ）受体拮抗剂ＣＰ９６３４５和ＲＰ６７５８０均能阻断中频、高频和变频的电针镇痛。ｉ．ｔ．注射阿片拮抗剂纳洛酮阻断低频和中频刺激时ＳＰ－ｉｒ含量的变化。结果提示，脊髓ＳＰ－ｉｒ在低频时释放减少，中频、高频和变频时释放增多有利于镇痛反应的实现。

It was found in the present study that low frequency(2Hz)electroacupuncture (EA)stimulation caused a decrease of the content of substance P immunoreactivity(SPir),whereas medium-(15Hz),high-(100Hz)and dense- disperse(D-D)-(2/15Hz) frequencies EA stimulation induced an increase of the content of SP-ir in the rat spinal fluid.EA analgesia induced by medium-,high- or D- D mode frequency was suppressed by nonpeptide SP(NK1) receptor antagonists CP96345 or RP67580 administered intrathecally (i.t.).Both the attenuation of SP release by low frequency EA and the potentiation of Sp release by medium frequency EA in the spinal cord were blocked by the opioid receptor antagonist naloxone(i.t.).These results suggest that a decrease of release of SP- ir by low frequency and an increase of it by medium-,high- and D-D mode frequencies in the spinal cord facilitate analgesia.