变频体表电刺激促使慢性痛患者脊髓中释放强啡肽

TRANSCUTANEOUS ELECTRIC NERVE STIMULATION OF IDENTIFIED FREQUENCY SELECTIVELY RELEASES DYNORPHIN IN SPINAL CORD IN PATIENTS WITH CHRONIC PAIN

本工作将皮肤电极置于人体穴位表面，用不同频率的方波脉冲进行电刺激，观察脑脊液中甲啡肽（ＭＥＫ）代谢片段ＭＥＫ１－４和ＭＥＫ２－４以及强啡肽Ａ（Ｄｙｎ－Ａ）含量的变化。观察结果如下：（１）急性和慢性疼痛患者脑脊液中ＭＥＫ１－４含量与正常组相比均无明显变化，但急性痛患者脑脊液中ＭＥＫ２－４及Ｄｙｎ－Ａ的含量显著低于正常人；（２）对照刺激或２／１５Ｈｚ变频刺激对患者脑脊液中上述神经肽片段的含量无明显影响，但２／１００Ｈｚ变频刺激后，慢性痛患者脑脊液中Ｄｙｎ－Ａ含量显著增加。韩济生实验室的动物实验结果表明，高、低频电针刺激可分别使大鼠脊髓释放Ｄｙｎ－Ａ和ＭＥＫ，并参与电针镇痛过程。本工作在疼痛患者身上也观察到不同频率的电刺激确可引起不同种类阿片肽的释放。这一发现可能有助于解释特定参数的电刺激对特定癌症的治疗作用。

Transcutaneous electric nerve stimulation(TENS) of different frequencies were delivered through skin electrodes placed on certain acupoints of the patients. Changes of the contents of opioid peptide dynorphin A(Dyn-A) and two metabolic products of another opioid peptide methionine enkephalin(MEK), MEK1-4 and MEK2-4 were observed in human cerebral-spinal fluid(CSF). The result showed that (1) the contents of MEK2-4 and Dyn-A in the CSF of patients with acute pain were decreased significantly compared with normal control level while the content of MEK1-4 remained unchanged in patients with acute or chronic pain; (2)TENS of 2/100Hz but not 2/15Hz elevated the CSF level of Dyn-A significantly in chronic pain patients. Our previous studies performed in rats in Han’s Laboratory showed that electroacupuncteure stimulation of 100-and 2-Hz increased the release of spinal Dyn-A and MEK respectively, which plays an important role in the mechanism of electroacupuncture-induced analgesia. Results obtained in the present study suggest that in patients with acute and chronic pain spinal opioid peptides can also be mobilized by peripheral electrical stimulation of specific frequencies.